OPERATION AND MAINTENANCE FlANUAL. with ILLUSTRATED PARTS LIST. for SPECIAL DISTRIBUTION BOX. with THREE 28.5 VOLT DC OUTPUTS AND

Transcription

1 i, OPERATION AND MAINTENANCE FlANUAL with ILLUSTRATED PARTS LIST for SPECIAL DISTRIBUTION BOX with THREE 28.5 VOLT DC OUTPUTS AND THREE 37.5 kva, 5/200-V AC, 400-Hz, 3-PHASE OUTPUTS CAPABLE OF USE WITH REMOTE PUSHBUTTON AND POKIER RECEPTACLE STATION manufactured by Hobart Brothers Company Power Systems Division Troy, Ohio '2- - -U S.A - -,.-~_~_

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3 I OM-324 TABLE OF COYTENTS SUBJECT PAGE NO.. Introduction 2. General Description i, 3,' Identification 4. Detailed Description A. Netal Box 3 5. Interior Panel Assembly 4 () Input power circuit 4 (2) Output circuit 4 (a) AC overload transformers and resistors and DC overload relays 4 (b) AC load contactor 4 (c) DC load contactors and overload relays 6 (d) AC overload module 6 (3) Rectifier (4) Control panel 7 7 (a) Power supply transformer assembly 7 (b) Filter assembly 7 (c) Auxiliary overload relay board 7 (d) Plug-interlock relay board 9 (e) Test-bank switches 9 (f) Indicating lights 9 (g) Reset switch 0 (h) Fuse 0 (k) Resistor 0 (m) Circuit breaker 0 April 25/83 Contents Page

4 OM-324 TABLE 0~ CONTENTS (CONTINUED) SUBJECT 5. Installation (5) AC output contactor switch panel i, (a) Safety switches (b) AC output contactor monitor board (6) Remote receptacle and pushbutton stations (a) Motor-generator remote control (b) AC output remote contra (c) AC output receptacle (d) DC output remote contra (e) DC output receptacle (7) Remote AC overload light connections A. General B. Preparing Box for Installation C. Installing Distribution Box D. Wiring the Distribution Box E. Grounding F. Positioning Switches 6. Operation A. General B. Delivering Power to an Aircraft or Similar Load C. Disconnect Power Methods 7. Maintenance A. Distribution Box B. Remote Power Receptacle and Pushbutton Station PAGE NO ' ' Contents Page 2 April 25/83

5 iia IZEI OPI-324 TABLE OF CONTENTS (CONTINUED) SUBJECT 8. Inspection A. General B. Inspection/Check 9. Testing A. General B. Test Procedures 0. Repair. Trouble Shooting A. General i ;, PAGE NO B. Trouble Shooting Chart 2 () (2) Description Use of trouble shooting chart 2 2 FIGURE NO. LIST OF ILLUSTRAl-IOMS TITLE PAGE NO. Fig. Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig, 7 Fig. 8 Fig. 9 Fig. 0 Fig. Fig, 2 Fig. 3 Fig. 4 Distribution Box Specifications and Characteristics Interior Panel Control Panel Control Switch Panel Distribution Box!lountina Dimensions Installation Connection Diagram Typical Distribution Box and Generator Set Installation 7 Remote Control and Power Receptacle Box (Not part of Distribution Box) Interior Panel Connection Diagram (486379) Control Panel Connection Diagram (48204) Contactor Panel Connection Diagram ( ) Distribution Box Schematic Diagram (48638) Trouble Shooting Chart (6 Sheets) 2 3 ii z: April 25/83 Contents Page 3

6 w I ON-324. Introduction This manual contains operation and maintenance information and instructions for an AC/DC Distribution Box (see Fig, ) manufactured by Hobart Brothers Company, Power Systems Division, Troy, Ohio This box is a special, custom design. i, The distribution box is available with three 37.5 kva, 400 Hz, 3-phase, 20,0/5 V output circuits with 37.5 kva total output capability. Three 28.5 V DC, 200 Amp outputs are also provided. A larger capacity,generator set would increase output capability. 2. General Description The distribution box (see Fig. ) consists of a metal enclosure which houses electrical power distributing equipment, The unit is designed to accept 200 kva, 5/200 V AC, 3-phase, 400 Hz power from a generator set and distribute it to three 400 Hz, 3-phase, 37.5 kva independently operated AC output circuits, Also, 28.5 V DC power received from a transformer rectifier (see separate manual) is applied to three DC output circuits each of which is controlled by load contactors in this box. Total output is set by the generator set. The distribution box is desiqned for operation by remote output and pushbutton control stations which are also manufactured by Hobart Brothers Copnpanv, Power Systems Division, Troy, Ohio, which is also included with this distrjbution box in this manual even though it is an accessory equipment, 3. Identification The distribution box is a specially designed model. All CorrespQndence requires the model number and part number for identifying this design. 4. Detailed Description All distribution boxes covered by the manual are identical with three AC and three DC output circuits. Larger generator output power ratings could be used without any change in the AC/DC distribution box so long as the output rating for each output circuit is not exceeded. A detailed description of parts used in the construction of the distribution box is given here. Main assemblies or functional groups are listed and components of each assembly or group are then described. (See Fig. 2 for specifications and capacities.) April 25/83 Page

7 OM-324 Feet not provided on some units. Page 2. Distribution Box Figure April 25/83

8 OM-324 PHYSICAL Weight approximately with mounting feet without mounting feet ti 800 pounds (363 Kg) 780 pounds (354 Kg) Height without mounting'feet 65 l/6 inches (650.7 mm) Height,(overall) approx.(incl.#tgl Feet)-77 l/6 inches (955. mm) Width approx. 60 l/6 inches (525.6 mm) Depth approx. l/4 inches ( mm) Height includes 3" for the removable lifting eyes, ELECTRICAL INPUT Capacity of shipped generator was 37.5 kva for 08A. Capacity (max.) (Maximum for 200 kva Generator) 577 A Volts 5/200 V AC Phase 3 Frequency 400 Hz OUTPUT - Total limited to the generator capacity. Sets of cables accommodated Three, Three Phase, 400 Hz, ZOO/5 Volt CABLES and Three 28.5 V DC, 200 Amp Output CABLES Capacity of Each Output Terminal (see NOTE below) 3 Phase, 400 Hz output 37.5 kva, 08 A 28.5 V DC Output (5.7 kw) 200 ADC NO-i-E: Generator Capacity Limits Sum to 37.5 kva, 08 A A. Metal Box Specifications and Characteristics Figure 2 The steel enclosure which houses electrical components is a steel NEMA 4 box (, Fig. ). It is equipped with two, 2-inch floor stands and two lifting eyes. The box is designed to house electrical equipment in outdoor areas, or in areas which are regularly hosed down, or otherwise wet. 'Each box is equipped with two hinged doors which will swing outward a full 80 degrees. The doors are held tightly closed against a neoprene gasket by screw clamps. A removable center post is installed between doors and serves as an attaching point for clamps. Additional clamps hold the doors at the top and bottom. Eight mounting studs are provided on the rear panel of the box for attaching a 56-inch by 56-inch interior panel. All exterior hardware is stainless steel, April 25/83 Page 3

9 B. Interior Panel Assembly The interior panel assembly (2, Fig. ) consists of all electrical components, mounted on a no. gauge, 56-inch by 56-inch steel panel (2, Fig. 3). The panel is attached to the rear of the box by eight studs and nuts, i, () Input power circuit '(a) DC input leads are connected from the transformer rectifier set to the positive input terminal (4) and negative terminal (4). (b) AC input power leads (A, B, and C) from the generator set are connected to cast aluminum cable lugs (9, Fig. 3) which are mounted on an insulated bracket near the lower right corner of the interior panel. Lugs are two-conductor type and will accommodate cable sizes No. 4 to GOOMCM. The neutral (N) lead from the generator is connected to one of the lugs on a terminal mounting board () in the lower left corner of the panel. (2) Output circuit For convenience we shall consider the circuit from the AC input bus bars (8) and the DC input points (3, 4) to the output terminal board () as the output circuit, There are three separate BC and AC output circuits in this distribution box. The following description applies to a single output circuit in the box. All circuits (three) are identical. The output terminals are identified in Figure 3. (a) AC overload transformers and resistors and DC overload relays Each of the three DC outputcircuits is protected by the DC overload relay (K743-K745) mounted on the DC overload relay panel (7, Fig. 3) to which the + input lead is connected, Each phase "A", "B", "C" in the output c i rcuit is routed by cable from the AC bus bars (8, Fig. 3) through an overload current transformer (5) to a load contactor (4). The three transformers in conjunction with three burden resistors (6), monitor the output load current in each of the three output phases, and supply a reduced value current signal to the overload module (7). (b) AC load contactor (4, Fig. 3) The AC load contactor provides a means of controlling each AC output circuit independently of other output circuits, The load contactor is a sealed unit containing four sets of contacts and a magnetic coil. Energizing the coil by pressing a remotely located "ON" pushbutton (9, Fig. 9) CLOSES all contacts and also turns ON an indicating light (0, Fig. 9). Contacts remain closed and the light remains ON as long as holding power is supplied to the coil. Three sets of large contacts in the contactor conduct the three-phase output. One set of smaller contacts by-pass the "on" switch to supply holding power to the coil when the "on" button is released. Page 4 April 25/83

10 5 I I I I n I I c I I%. AC n OUTPUT f 0 2 i3 ii is 7 IO I4 9. Output terminal panel 0. Contactor switch panel 2. Control panel, 3 AC circuits ii. ;;;;;a terminals, 400 Hz 3. Rectifier (CR70-CR703) 4. AC load contactors (K70-K703) 3: Negative input, 28.5 V DC 5. Overload transformer (No, circuit) -4, -Positiveminputi-28;5 V 3C 6. Resistor (40 ohm, 25 ti; 37.5 kva) 5. Terminals, DC output pushbutton 7. Overload module 6. DC load contactors, K740-K Bus bars, AC input 7. DC overload relays, K743-K Input terminals, 400 Hz, 3-phase Interior Panel Figure 3 April 25/83 Page 5

11 , _-.---_.I _ -\_.,!., /--,.,.. j_ ~..... \ _ \ / ;< -. / I, -: / I, - I-- x ~ ~----m._:d.-..: ::-. : : I- - I..< _._; \!!,. -._ r-- - QM-324 -~~. ;- Pressing the "off" pushbutton (, Fig. 9)'breaks the holding circuit and allows the,.contactor to OPEN. Typically, a power available light (4, Fig. 9) glows when motor generator power is available to the output circuit contactor when the remote motor-generator start button (2, Fig. 9) is on. Power terminals mounted on the output terminal, panel (, Fig. 3), further identified by a silkscreened plexiglass cover, are provided for connecting each pair of the three AC and DC o,utputs to a remote station (Fig. 9) such as Hobart Brothers No supplied with the first order. (c) DC load contactors and overload relays (6,7; Fig. 3) WARNING: HIGH CURRENT DC ARCS CAN INJURE AND CAUSE FIRES! DISCONNECT TRANSFORMER RECTIFIER BEFORE SERVICING. Each of the three DC output circuits has its own DC contactor (K740-K74) each of which has a reverse current trip coil for protecting the equipment from large back feed of current. Additionally, each DC output circuit has its own DC overload relay (K743-K745) to which the positive DC input (4, Fig, 3) is directly connected. This circuitry is connected to the remote station switches per the diagrams. (d) AC overload module (7, Fig. 3) The AC overload module (7) is a solid-state device designed to interpret signals from transformers (5) and to send a signal to the auxiliary overload relay (6, Fig. 4) when an overload condition exists in any generator AC output phase. A pull-apart electrical connector is mounted on the overload module to provide quick-disconnect facilities for all wiring to the module. The overload module is equipped with a hermetically-sealed, reed-type relay. Relay contacts are normally open. The solid-state circuitry is designed to close relay contacts when output current in ANY phase reaches 25% of normal rated output capacity. The signal to the auxiliary overload relay causes a set of contacts in the load contactor holding circuit to OPEN and thus deenergizes the load contactor operating coil, causing the load contactor to OPEN. The following is a list of overload module characteristics: NOTE: The overload protective system will function when any - phase carries 23% to 27% of rated load. All times are plus or minus 25% and are nonadjustable. At 25% load the module will function in 5 minutes. At 50% load the module will function in 6 seconds. At 200% load the module will function in 4 seconds. -.._ I^. -..,-. April 25/ ~ --.-_---.-_. ~~~ -Page 6 -.

12 NOTE: Distribution box components and the aircraft are protected against..over and undervoltage, over and underfrequency, and excessive total load by protective devices in the power source (generator set) which function to cut off power to all boxes in the event of such faults. (3) Rectifier (3, Fig!'3) Each of three diode-bridge rectifiers (CR70-CR703) receives 400 Hz AC from phase C of the generator output and converts it to a pulsating, direct current for energization of its load contactor holding coil only. This DC coil-holding circuit is controlled indirectly by controlling the 400 Hz AC to the rectifier. Any time the overload monitor functions to open the auxiliary overload relay, the rectifier's AC circuit is opened. Consequently no DC power is then available to the load contactor coil and the load contactor opens. (4) Control panel (see Figure 4) The control panel (2, Fig. 3) is mounted at the top of the interior panel. It contains protective devices, controls, lights, etc. for the three 400 Hz 3-phase output circuits. (a) Power supply transformer assembly (7, Fig. 4) This assembly consists of T79 transformer, CR736 rectifier, and C707 capacitors. The assembly converts 5 V DC power to 24 V DC power for operation of the overload modules and overload indicating lights. After the transformer reduces 5 V ACto 24 V AC, the rectifier changes it to a pulsating 24 V DC. The 3 MFD capacitor prevents the pulsating voltage from reaching zero at its low fluctuation point. (b) Filter assembly The filter assembly (0) consists of L70 transformer, C708 capacitor and R704 resistor. The transformer serves as a choke to smooth the 24 V DC power. The 20 MFD capacitor helps maintain the output near 24 V DC. A resistor provides a 200 ohm load on the 24 V DC circuit to protect capacitors when the generator set is operating at no load, (c) Auxiliary overload relay board (5, Fig. 4) Four plug type relays are mounted on this board. Three are auxiliary overload relays (6); one for each AC output circuit. 'One set of contacts in each overload relay is connected in the AC load contactor energizing hold circuit. At a signal from the overload module, the relay functions to open the AC load contactor hold circuit and disconnect output power in the affected circuit. An overload indicating light (2) is turned on by the overload module at the same time. The light will remain ON and the relay will remain energi~zed until a res-et switch (4)'is'pushed to break the April 25/83- circuit. Page 7

13 O!?-324 No. I NO.2 NO.3 J.~~ - Circuit breaker (5-A), CB706 Overload indicating lights, local 0. Filter assembly. Spare relay (replaces all) Fuse (2-A), F70 2. Plug-interlock relay, K707-K709 Overload reset switch, S70 3, Resistor (25 ohm, 25 watt) Overload relay~board~-m ~~~~ 4. Test-ban~k switch, S70--S703 Auxiliary overload relay, K75-K77 5. Terminal board Power supply transformer assembly 6. Plug, 5703, overload Fuse-interlock relay, K Plug, 5702, interlock Plug-interlock board 8. Remote overload light connectio,ns Control Panel Figure 4 Page 8 April 25/83

14 A single fuse-interlock relay (8) is located in the lower right corner of the board. The contacts of this relay are located in the AC load contactor energizing system ground circuit. The relay coil must be energized by the 24 V DC overload protective circuit to hold relay contacts closed before any load contactor can be closed. In the event of a blown fuse or other disabling/fault in the 24 V DC system, the fuse-interlock relay contacts will OPEN and either cause ALL AC load contactors to OPEN, or prevent them from CLOSING. Although their functions are different, overload relays and the fuseinterlock relay are identical. All relays are identified by circuit number and electrical symbol which are silk-screened on the board. (4 Plug-interlock relay board (9, Fig. 4) This board is similar to the auxiliary overload board above. It also uses four relays. Three are functional plug-interlock relays (2). One is a spare () and is mounted in the lower right corner, All relays on the two boards are identical and may be replaced by the spare. The DC output plugs DO NOT HAVE THIS PROTECTION. Plug-interlock relay contacts are located in the AC load contactor operating coil circuit and must be closed by 28.5 V DC power from the aircraft before the contactor can be closed. The function of the plug-interlock relay is to cause the AC output load contactor to open if the AC cable plug connector becomes accidentally disconnected from the aircraft during power delivery, or if an attempt is made to deliver power when the output cable is not connected to the aircraft. Twenty-eight-volt direct current for operation of the relay is;supplied from the aircraft either through an on-board transformerrectifier, or from a twenty-eight-volt, electrical system. Connection from the aircraft to the interlock relay is made through terminals E and F on the cable connectors, (e) Test-bank switches (4, Fig. 4) DANGER: ELECTRIC SHOCK CAN KILL: DO NOT ATTEMPT TO REMOVE LOAD BY UNPLUGGING THE OUTPUT CABLE, DC OUTPUT PLUGS ARE NOT PROTECTED BY TEST BANK SWITCHES OR PLUG INTERLOCKS. Each AC output circuit is equipped with a single-pole, single-throw toggle switch, S70-S703. The switch provides a means of by-passing the plug-interlock relay contacts when supplying power to a load bank, or to an aircraft not equipped with a plug-interlock system. I (f) Indicating lights (2, Fig. 4) The function of these lights (DS706-DS708 for local and DS3-DS73 for remote) is to indicate to the operator.which output circuit was opened by an overload condition. The light will remain ON until the reset switch (4) is pushed. Remote overload lights are connected to the terminal board (5) above the overload--relay -board-~(5): April 25/83 -Pa-ge 9

15 (g) Reset switch (4, Fig. 4) This pushbutton switch (S70) must be pushed to break the overload module 24 V DC circuit, turn OFF the indicating light, and allow the auxiliary overload relay to return to CLOSED position. (h) Fuse (3, Fig. 4),The 24 V DC circuit is protected by a 2-A cartridge type fuse (F70). (k) Resistor (3, Fig. 4) A 25-ohm, 25-watt resistor protects the load contactor operating circuits in the event of a blown diode in a rectifier. (m) Circuit breaker (, Fig. 4) A 5-A, manual reset circuit breaker (CB706) protects all AC output load contactor operating pushbutton circuits. (5) AC Output contactors switch panel (0, Fig. 3) The contactor switch panel (see Fig. 5) is mounted at the lower edge near the center of the panel. It consists of safety switches and monitoring instruments mounted on a rectangular panel. (a) Safety switches (6, Fig. 5) A safety toggle switch is provided for each AC output circuit. The switch functions to open and disable the AC load contactor operating circuit and thus prevent its closing by operation of a remotely located pushbutton switch. This feature allows an electrician to disable one or all AC output circuits and work on components with more safety. A safety.bock pin (7) with ball detent and pull ring is mounted in a guard bracket above each switch to add extra safety and prevent inadvertent actuation of the switch. (b) AC output contactor monitor board (, Fig. 5) The contactor monitor board provides mounting for a series of light emitting diodes (5). Each diode is connected to a single output phase and emits a red light when the phase is energized. If all three phase lights (A,B, and C) in an output circuit are off, it indicates that the load contactor for that circuit is open. These lights are also helpful in trouble shooting. For example, if only two lights in a circuit are glowing when the contactor is closed, it indicates that one set of contacts in the load contactor are defective and the load contactor should be replaced. If one of the three phase lights remains on when the contactor is open, it indicates that the load contactor contacts for that phase are stuck, fused together, or otherwise defective and the load contactor should be replaced. Page 0 April 25/83

16 OM Contactor monitor board Indicatinq lights (light emitting diode) :: Connector, Circuit disabling toggle switch, 3. Resistor (0,000 ohms, 0 watts) S72-S723 4, Diode (400 PRV,.5-A) 7. Safety pin April 25/83~ Contactor Switch Panel. Figure 5

17 0M-324 A 0,000 ohm, 0 watt resistor (3) is connected in series with each light emitting diode..to reduce voltage to a value (approximately volt) which will not destroy the diode. A 400 PRV,.5-A silicone diode (4) is connected in parallel with each light emittinigldiode, This protection is necessary because the light emitting diode has a very low peak reverse voltage capacity. (6) 'Remote Receptacle and Pushbutton Stations (see Fig. 9) The distribution box is designed to use a remote output receptacle and to use remote pushbutton controls such as provided by the Hobart Brothers assembly described here. This aosessory is typically located some distance from both the generator set and the distribution box. This particular accessory provides for control of a single 400 Hz 3-phase, looa, 5/200 V output circuit, a single 200 Amp, 28.5 V DC output circuit, onoff control of the associated generator set, and the separate output receptacles for the two outputs. (a) Motor-Generator Remote Control(2, Fig. 9) This control works with the remote contactor option generator set for remote turn on using the start pushbutton (2) and turn off in case of an emergency with the emergency stop pushbutton (3). The amber light (4) on this remote control glows whenever power is available to the distribution box. Since one generator set serves more than one remote station, the emergency stop pushbutton should not be used except in an emergency or if the other stations are not being used. (b) AC Output Remote Control (8, Fig. 9) The close pushbutton (9) allows the operator to turn on the output contactor for the 37.5 kva, 3-phase, 5/220 Volt, 400 Hz output so long as the power available light (4) is on and the plug interlock relays and the overload protection circuits don't prevent operation. The "OPEN" pushbutton () allows remote turn-off of the output without disturbing other remote power distribution stations, The contactor closed light (0) remains on after the close contactor pushbutton is operated if the power output circuitry is proper. (4 AC Output Receptacle (4, Fig. 9) This heavy duty, weather-protected receptacle connects the AC load using a matching 00 Amp plug attached to the load cable, WARNING: ELECTRIC SHOCK CAN KILL AND ARCS CAN INJURE! DO NOT UNPLUG ENERGIZED PLUGS. OPEN CONTACTOR FIRST. Page 2

18 OM-324 (d) DC Output Remote Control t3, Fig. 9) The close pushbutton (5) on this control allows the controlling DC contactor (6, Fig. 3) to pick up so long as the generator set power available light (4) is on, the transformer-rectifier unit is connected/&d operating properly, and the DC overcurrent circuitry (7, Fig. 3) and reverse current trip circuitry or interlock circuitry are not tripped. The DC contactor open pushbutton (6) opens the DC contactor or load without disturbing the other output loads, The DC contactor closed light (7) glows whenever the DC output circuitry is supplying power to its load. (e) DC Output Receptacle (5, Fig. 9) This heavy duty, weather-protected receptacle connects the 28.5 Volt DC load up to 200 Amperes continuously using a matching 200 Amp plug attached to the DC load cable. blarning: ELECTRIC SHOCK CAN KILL AND ARCS CAN INJURE! DO NOT UNPLUG ENERGIZED PLUGS. OPEN COMPACTOR FIRST. THE DC OUTPUT DOES NOT HAVE PLUG INTERLOCKS. (7) Remote AC Overload Light Connections (8, Fig. 4) 5. Installation These three AC outputs circuit overload trip light connection points are for the customer's own optional 28 Volt DC remotely installed overload fault lights. Refer to the distribution box instaliation diagram for wiring details. A. General Since the box, which houses electrical components, meets NEMA standards for "Type 4-Watertight" enclosures, it may be installed either indoors or outdoors. See Fig. 8 for a typical installation. B. Preparing the Box for Installation There are no holes or openings in the box for input and output cables. Determine the type of box connectors (conduit, pipe, cable horn, etc.) to be used and cut holes to accommodate the connectors selected. Connections should be waterproof. C. Installitig Distribution Box Unless removed, the box has two floor stands, or "mounting legs". Each stand has three, 7/6-inch diameter, mounting holes. When the exact mounting location has been selected, fasten the distribution box securely to the floor with lag screws, or cement embedded studs. (See mounting dimensions in Fig, 6) April 25/83

19 - q ; 52 E OK5 r I tt -o- L )I o I I 2 i, 0 --o- 0-3 D. Wiring the Distribution Box Distribution Box Mounting Dimensions Figure 6 Install and connect input and output leads and/or cables in accordance with Installation Diagram Figure 7. Plug-interlock terminals ("E" and "F") on the output terminal board are "jumpered" so that only one "E" or "F" lead is required in a multi-conductor cable between the box and aircraft. Connect to either "E" or "F" terminal. Connect remote control leads at terminal boards (5, Fig. 4) on control panel. BE SURE ALL LEAD AND CABLE ATTACHING HARDWARE IS TIGHTENED SECURELY AND ALL LEADS AND CABLES ARE SECURED FROM PINCHING, CUTTING, AND ABRASION DANGER. E. Grounding The distribution box is grounded through the powersource when the "" lead from the generator set to the solid neutral terminal (, Fig. 3) is connected. However, if additional grounding is desired, or called for by local electrical code, connect a ground lead between the solid neutral terminal and one of the box mounting lag screws or studs. F. Positioning Switches Before closing and fastening the distribution box doors, place all testbank switches (4, Fig. 4) in Aircraft position so that plug-interlock relays will be functional. Be sure circuit breaker () is in ON position. Be sure all circuit disabling switches (6, Fig. 5) are locked in ON position (opposite Disable). NOTE: Place test bank switches in Test Bank position for power delivery to a load test bank, or aircraft not equipped with plug-interlock system. See WARNING below. DANGER: ELECTRIC SHOCK AND FIRE CPM KILL! DO NOT TOUCH ENERGIZED PARTS. READ AND UNDERSTAND THESE INSTRUCTIONS-BEFORE OPERATING. TURN OFF CONTACTOR BEFORE UNPLUGGING LOADS. Page 4 April 2583

20 I I OM Operation A. General Each distribution box output circuit is typically operated from a remotely located power receiptacle and control box. Each remote box controls a corresponding output circuit in the distribution box and also has means of starting, stopping, and monitoring the generator set output if the remote contactor option is specified. B. Delivering Power to An Aircraft or Similar Load To deliver power to an aircraft, proceed as follows: () With the output contactor OPEN (DEENERGIZED), insert the proper output cable plug in the output receptacle. Be SURE the'connectors are fully mated and secure at all points in the circuit. (2) Check amber indicating light (4, Fig. 9) in the remote control box to verify power is available at the distribution box. (3) For 28.5 V DC output loads, press the contactor close pushbutton (5, Fig. 9) and observe that the clear light (7) remains on showing that power is available at the load. (4) For 3-phase, 400 Hz, 5/200 V output loads, press the AC contactor "on" switch pushbutton (9, Fig, 9) and verify light (0, Fig. 9) should glow immediately and remain ON to&indicate that the AC lcad contactor has closed and power is available at the aircraft or similar load. NOTE: In the event that an AC load contactor is OPENED by an overload condition, the reset switch (4, Fig. 4) must be pushed after the overload is corrected to turn OFF the overload indicating light and return the overload safety circuit to normal. The overload,reverse current, or other fault condition causing the DC contactor to trip must be corrected before the DC output can be restarted. The contactor control circuit breaker (, Fig, 4) must also be manually reset for proper operation when tripped. C. Disconnect Power Methods () To remove AC output without disturbing other outputs, press 400 Hz output "OPEN" switch pushbutton (, Fig. 9). The indicating light (0) should go off indicating the load contactor has opened'and AC power has been disconnected from the aircraft. Disconnect output cable plug (AC) from aircraft or similar load. (2) To remove DC output power without disturbing other outputs, press DC contactor "OPEN" pushbutton (6, F.ig. 9) and verify the indicating light (7) goes off before disconnecting the DC output cable plug-from the aircraft or similar 28.5 V DC load. April 25/83 bge 5

21 Page 6 Installation Connection Diagram Figure 7

22 (3) For emergency turn-off of power to the distribution box and to all loads, press emergency stop pushbutton (3, Fig. 9) to stop generator. TL, REMOTE STATION NO. 2 AC 8. DC OUTPUT 2 AC & DC OUTPUT u TO REMOTE STATION NO. (See Fig. 9) DANGER: ELECTRIC SHOCK AND FIRE CAN KILL! DO NOT DISCONNECT A CABLElPLUG WHEN POWER IS ON. I I II I AC & DC OUTPUT NO. 3 TO REMOTE STATION 3 (See Fig. 9) I II AC INPUT FROM GEN. II u DC INPUT FROM GEN. 7 -I- Y - I-- 0 stri bu- MOII Box 7. Maintenance Typical Distribution Box and Generator Set Installation [psd-o60] A. Distribution Box Figure 8 The distribution box requires no maintenance, as such, and should operate for long periods without attention, No lubrication is required. Contactor contacts and plug in relays require infrequent replacement as needed. B. Remote Power Receptacle and Pushbutton Station April 25/83 Except for indicator lights and pushbutton switches which normally provide good service life, no parts requir,e periodic replacement, re~pair or attention if used properly within their rating.

23 8. Inspection A. General The distribution box and remote station require a minimum of inspection and, checking. Inspectioblperiods of less than one year intervals are not recommended. B. Insp,ection/Check 9. Testing Page 8 DANGER: ELECTRIC SHOCK CAN KILL! BE SURE INPUT POWER IS OFF BEFORE OBTAINING ACCESS TO COMPONENTS. Inspect the complete unit anytime a requirement for opening the doors occurs. () Inspect ALL lead connections and terminals for security. (2) Visually inspect all components and connections for discoloration and evidence of overheating. (3) Inspect and check all attaching hardware for security. (4) Inspect door gaskets for defects which would allow leakage. (5) Set test bank switches to "Aircraft", circuit breaker to ON, and disabling switches to output ON position opposite "DISABLE". A. General NOTE: When securing doors after inspection or repair, be sure gaskets fit properly and all door clamp screws are tightened. Full 37.5 kva power, which is normally connected to the distribution box, is not necessary for testing. The box may be tested with as little as 20 kva. DANGER: ELECTRIC SHOCK CAN KILL! BE SURE POWER IS OFF BEFORE WORKING WITH TERMINALS AND CONNECTIONS. B. Test Procedures () Connect the generhtor set providing the 37.5 kva, 3-phase, 5/220 Volt, 400 Hz and the 28.5 V DC power to their respective input terminals. (2) Connect the remote output control cables to terminals for No. output circuit at terminal board.(l5, Fig. 4) and connect the generator on-off control cables, if used, to the motor generator control terminals.

24 6 Remote Control and Power Receptacle Box (Not part of Distribution Box) Figure 9 (3) Connect No. AC output circuit to a load bank capable of applying a 27% load (37.5 A, 3-phase, 5/200 Volt, 400 Hz for 37.5 kva rated output if no 28.5 V DC power is supplied at the same time.) Connect a source of 28 V DC power (two, 2 V batteries connected in series will do) to terminal "Et' or 'IF" on No. output circuit. Be sure batteries are properly grounded to "N" terminal. (4) Place test-bank switches (4, Fig. 4) in Aircraft position. Press generator set start pushbutton (2, Fig. 9) and verify power available light (4, Fig. 9) glows. (5) Adjust test bank to apply a full load (08 A if 3-phase, 400 Hz is only output). 6) Check all fault lights (2, Fig. 4) and breakers (, Fig, 4) for no-trip condition, April 25/83 Page 9

25 (7) (8) Check the indicating lights in remote control box for circuit being tested. Only the power available light should be ON. Press the AC output No, remote CLOSE pushbutton (9, Fiq. 9) and verify AC contactor CLOSED light (0, Fig. 9) stays on. - (9) Press AC output/open pushbutton and verify contactor CLOSED (0, Fig, 9) goes off. light (0) Turn AC output No. on again per B,(8) above. Verify that indicating lights (5, Fig. 5) for No. Circuit A, 8, and C glow red. all three Phase () Operate with a full load for 30 minutes. Load contactor should be opened by any safety device. not (2) (3) Disconnect 28 V DC circuit (batteries) from "E" or "F" terminal in output circuit being tested. With test-bank switch for that circuit in Aircraft (OFF) position, the load contactor should not close when control box ON button is pushed. Load contactor should close with test bank switch in "TEST BANK" ON position. With overload (27% normal load) applied to No. circuit, the overload protection circuit should function within 5 minutes to: st - Open load contactor 2nd - Turn on No. overload indicating light 3rd - As a result of load contactor opening, the light emitting diode (5, Fig. 5) indicating lights should be turned OFF. (4) Remove load and press reset switch (4, Fig. 4). il5> (lf2 Repeat above tests for each of remaining AC output circuits to be tested, The DC output circuits may be checked in a similar manner except for overload testing. The 200 Ampere plug rating must not exceed 275 A DC for the output testing. Each DC output circuit should trip in minute at 275 A and carry 225 A, for 5 minutes. Continuous rating is 200 A 28.5 V DC. Adjustment of trip points is by dashpot height adjustment on the DC overload relays K743-K745 (7, Fig. 3). 0. Repair Repair will consist primarily of parts replacement. When working on any AC output circuit or AC output cable, remove safety pin (7, Fig. 5) and place disabling toggle switch (6) in DISA5LE position so that the AC load contactor for that circuit cannot be closed inadvertently from a remote control box, Replace safety pin so that switch cannot be accidentally turned ON. Page 20 _ April. 25/83

26 DANGER: ELECTRIC SHOCK CAN KILL! DO NOT TOUCH LIVE PARTS. REMEMBER THAT AN OUTPUT CIRCUIT IS OIilLY DISABLED FROM THE LOAD CONTACTOR OUT- WARD. THE REMAINDER OF THE CIRCUIT FROM LOAD CONTACTOR BACK TO BUS BARS AND ALL CONTROL CIRCUITS ARE "HOT" AS LONG AS POWER IS BEING DELIVERED TO THE BOX. THE DISABLE POSITION DOES NOT WFFECT THE DC OUTPVT, CI RCUITS.. Trouble Shooting A. General () Trouble shooting is an orderly process of checking and eliminating possible causes of trouble until the exact cause of a trouble is found. As a rule, the best place to start looking for the cause of a trouble in a circuit is at the source of power. Continue testing and checking the circuit, step-by-step, with suitable equipment in an orderly manner, until the cause of trouble is located. (2) This section provides information useful in diagnosing and correcting certain troubles which cause unsatisfactory operation or failure of the equipment. (3) Minor troubles may be remedied by the operator; however, major repairs must be undertaken by experienced mechanics and electricians only. B. Trouble Shooting Chart (Figure 4) () Description The trouble shooting chart lists information under three headings: (a) Trouble, symptom, and condition (b) Probable cause (c) Test, check, and remedy (2) Use of the Trouble Shooting Chart The trouble shooting chart is intended to provide maintenance and repair personnel with a time-saving guide for locating the source of a trouble. A schematic diagram (Fig. 3) is included to assist in trouble shooting. April 25/83 DANGER: ELECTRIC SHOCK CAN KILL! EXERCISE EXTREME CARE TO AVOID CONTACT WITH HIGH VOLTAGE LEADS AND COMPONENTS WHICH COULD CAUSE SERIOUS OR FATAL INJURY IF TOUCHED WHEN TROUBLE SHOOTING OR OPERATING THE EQUIPMENT. HIGH CURRENT ARCS EVEN AT LOW VOLTAGE CAN INJURE AND CAUSE A FIRE HAZARD ~~ -~~~- Page 2

27 Interior Panel Connection Diagram Figure 0 Page 22 April 25/83

28 48204 Control Panel Connection Diagram Figure April 2583.~ Page 23

29 Contactor Panel Connect Figure 2 Page 24

30 OM Distribution Box Schematic Diagram Figure 3 April 25/83 Page 25

31 TROUBLE, SYMPTOM AND CONDITION PROBABLE CAUSE TEST, CHECK, AND REMEDY OM-324 AC LOAD CONTACTOR CONTROL CIRCUIT NOTE : Since the distribution box;js operated from remote stations, any troubles will be detected first at a station. Eefore condemning 'the distribution box as alsource of trouble, check the remote control box thoroughly by checking indicating lamps, switches, and circuitry, It is assumed that all external sources of trouble have been eliminated before using th.is chart and that the generator set is on.. Power available NOTE: The power available indicating light is powered by indicating light the generator set proper functioning and the on remote control remote control lamp circuit integrity including box does not glow input power to distribution box, when it is known that power is A. Circuit breaker (, A. Check circuitry to determine available at Fig. 4) tripped cause of tripping. Correct distribution box fault and reset circuit breaker. B. 24-V DC power for B. Check as follows: closing the fuse interlock relay (8, Fig. 4) may be disrupted by a fault in one of the circuit components () Fuse (3, Fig. 4) blown (2) Defective power transformer assembly (7, Fig. 4) () Check fuse and replace as required. Check circuit for cause of fuse blowing. (2) Check transformer (T79) output. Should be approximately 24-V AC. Check rectifier (CR736). Output should be pulsating 24-V DC. Check capacitor (C707). Should not be OPEN or shorted, Replace components or complete power transformer assembly if defective. Page 26 Trouble Shooting Chart (Sheet of 6) Figure 4 April 2583

32 I OH-324 I I TROUBLE, SYMPTOM AND CONDITION,.PR@BABLE CAUSE TEST, CHECK, AYD REr9EDY AC LOAD CONTACTOR CONTROL CIRCUIT (CONTIWED). Continued B.i C,o+i nued (3) Defective filter assembly (0, Fig. 4) (4 ) Fuse-interlock relay (8, Fig. 4) defective 3. Continued (3) Check choke (L70), capacitor (C708) and resistor (R704). Replace defective component or complete filter assembly. (4) A spare relay (, Fig. 4) is supplied on interlock relay boards. Remove suspected defective relay and install spare. If power available light will now glow, discard defective relay, and replace spare relay with a new one. (5) Disabling toggle (5) Switch must be locked switch (6, Fig. 5) in output OR position. set to DISABLE or Check switch continuity, defective Replace if defective. 2. AC load contactor will not close. Power available light ON at remote control box. (6) Defective auxiliary overload relay (6, Fig. 4) (7) Defective resistor R705 (3, Fig, 4) (8) fior,ei R;;tifier, i. A. Defective component in AC load contactor control circuit (6) Replace suspected relay with spare (, Fig. 4) as in step (4) above. If light will now glow, discard defective relay and place a new relay in spare socket. (7) Check resistor. Replace if open or shorted; i.e., not 25 ohms. (8) Check and replace if bad. i. Check as follows: April 25/83 Trouble Shooting Chart (Sheet 2 of 6) Figure 4 Page 27

33 TROUBLE, SYMPTOM AND COHDITION PROBABLE CAUSE TEST, CHECK, AriD REMEDY OM-324 AC LOAD COT~TACTOR CONTROL CIRCUIT (CONTINUED) 2. Continued A. Contiptied A. Continued NOTE: When power available light is ON, it indicates that the disable switch, auxiliary overload relay, fuse-interlock relay and circuit breaker are good. The only remaining components which could prevent the load contactor from closing are the rectifier (3, Fig. 3) and load contactor (4, Fig. 3) coil for that output circuit. () Defective rectifier (3, Fig. 3) () Check diodes in suspected rectifier (CR70- CR705). If any diode is open or shorted, replace rectifier, (2) Defective coil in (2) Use terminals "Y" and AC load contactor "X" to test coil resis- (4, Fig. 3) tance. Resistance should be approximately 600 ohms. If coil is defective, replace complete load contactor. 3. AC load contactor A. A component in the A. Check as follows:, will close but load contactor "hold" OPEhlS as soon as circuit is defective control box OPI button is released. () Output cable not () Connect output cable properly plugged into aircraft plug to aircraft receptacle securely so that components are fully mated. (2) Defective "E" and "F" terminals in cable plug connector or receptacle (2) Inspect plug and receptacle thoroughly. Repair or replace as required. (3) Aircraft not sup- (3) Check aircraft onboard plying 28.5-V DC equipment to make cer-' to plug-interlock tain that aircraft will relay accept power and return 28.5-V DC power to terminals "E" and "F" on.output terminal panel. Trouble Shooting Chart (Sheet 3 of 6) Page 28 Figure 4 April 25/83

34 w OM-324 TROUBLE, SYMPTOM AND CONDITION PROBABLE CAUSE TEST, CHECK, AND REMEDY AC LOAD CONTACTOR CONTROL CIRCUIT (CONTINUED) 3. Continued Ah ;Continued A. Continued (4) Defective plug- (4) If contactor will interlock relay remain closed when (2, Fig. 4) test-bank switch is ON, replace plug interlock relay with spare (, Fig. 4) (5) Defective small "hold" contacts in load contactor (4, Fig. 3) (5) Connect a jumper lead between terminals and 2 on load contactor to b.y-pass hold contacts (see Connection Diagram, Fig. 0). If load contactor will now remain closed, replace complete load contactor see NOTE in Para. 4, B, (2, CAUTION : DO NOT OPERATE THE WIT HITH ANY COMPONENT(S) JUMPERED EXCEPT Fr)R CHECKING FOR A SHORT TI[!E. 4. AC load contactor opens during power delivery A. Output cable has been A. Reconnect cable pluq accidentally discon- securely and proceed with netted from aircraft power delivery. B. A temporary overload A. Open distribution box and condition has caused press reset switch (4, load contactor to Fig. 4). Correct condition open that caused overload. C. If load contactor cannot be closed for operation, a component in the contactor operating circuit has likely failed or a loose connection exists. D. If power available light is off, the generator set may have tripped, C. Check load contactor operating circuit in accordance with TROUBLES, 2, and 3 above. D. Check generator set for trip indications using generator,set manual. If tripped, remove cause of problem and restart. April 25/-83 Trouble Shooting Chart (Sheet 4 of 6) Figure 4 Page 29

35 TROUBLE, SYMPTO!d AND CONDITION I PROBAB.LE CAUSE TEST, CHECK, AND REMEDY ntjt 29A AC OVERLOAD SENSING AND OPERATING CIRCUIT. Overload,circuit A. One oflthe resistors A, An open resistor will cause functions to OPEN (6, Fig.'3) across a higher than normal voltage load contactor when overload transformers signal to overload module no overload exits. is open circuited (7, Fig. 3). Check resistors and replace as required. 2. Overload circuit A. Failure in 24-V DC A. Check power supply in accorwill not function power supply dance with TROUBLE, 6. under overload B. Shorted overload B. Replace shorted resistor or transformer or overload transformer. resistor 3. Overload light (2, A. Defective overload A. If overload module is Fig. 4) remains ON module (7, Fig. 3) defective, replace complete after reset switch module, Return old module (4, Fig. 4) has to Power Systems Division, been pushed. Attn: Service Dept., for exchange,!. Overload light comes A. Defective auxiliary ON, but load contac- overload relay (6, tor'does not open. Fig. 4) B. Shorted output contactor load contacts A. Use spare relay (, Fig. 4) to replace. Be sure to place new relay in spare socket. B. Check visually with pqwer from generator set turned off. Replace the contactor if contacts are welded together. Page 30 Trouble Shooting Chart (Sheet 5 of,6) Figure 4 April 25/83

36 TROUBLE, SYMPTOM AND CONDITION,.PROBABLE CAUSE TEST, CHECK, AND REMEDY DC LOAD CONTACTOR CONTROL UNIT. DC,contactor CLOSED 28.5-V DC input A. If 28.5-V DC is not present light (7, Fig. 9) power to box from 4 (+) to 3 (-) in does not glow when Fig. 3, troubleshoot transclose pushbutton.(5) is pushed former-rectifier using its manual. 5. Polarity switched at 5. Verify + for 28.5-V DC is input terminals or DC at DC contactor terminal contactor marked "GEN" and - for 28.5-V DC is at terminal marked "GD". t C. DC overload relay faulty or tripped 2. DC contactor CLOSED A. Bad DC contactor light glows but no DC output. C. Check for + 28-V DC at DC contactor open pushbutton with other lead of voltmeter on "GD". If not present, check for DC fault and faulty DC overload relay (K743-K745). If voltage exists, the wiring or bulb is faulty or the DC contactor coil is shorted (very unlikely without smoke). A. Check coil "SW" 'to "GD" for 28-V DC. If present and "BAT" to "GD" voltage remains zero, replace contactor. 5. Open DC power lead to B. Check if 2.A. right. remote box receptacle Trouble Shooting Chart (Sheet 6 of 6) April 25/83 Figure 4 Page 3

37

38 PARTS LIST HOBART BROTHERS CO., TROY, OHIO U.S.A. SPECIAL DISTRIBUTION BOX HOBART NO wi tti REMOTE POWER RECEPTACLE AND PUSHBUTTON STATION HOBART NO

39

40 OH-324. TABLE OF CONTETiTS SUBJECT CWAPTER/SECTION PAGE Introduction 'General Purljose Arrangement i, l-l, Explanation of Parts List Contents Parts List Form "Figure-Item No." Column "tlobart Part No." Column 2 2 "t~omenclature" Column 2 Yanufacturer's "Eff" (Effective) Column "Units Per Assembly" Column Codes l Parts Explanation of Manufacturer's (Vendor's) Code List List General l-3 Symbols and Abbreviations Distribution Interior Box Assembly Panel Assembly 2 4 Output Terminal Board Group 8 Neutral Terminal Panel Assembly lc: Input Terminal Group 2 Control Panel Assembly 4 Contactor Switch Panel Assembly 8 April 2583 Contents Page

41 ON- 324 TAGLE OF CONTENTS SUBJECT CHAPTER/SECTION PAGE Numerical Index l-4 Explaiation of Numerical Itkic Contents Page 2 April 25/83

42 . General The Illustrated Parts List identifies, describes, illustrates main assemblies, subassemblies and detajll, parts of a ground power Distribution Box, manufactured by Hobart Brothers Company, Power Systems Division, Troy, Ohio, and identified as Hobart Part No and a remote power receptacle and control pushbutton box used as an accessory to it. 2. Purpose The purpose of the Illustrated Parts List is to provide parts identification and descriptive information to maintenance and provisioning personnel for use in the provisioning, requisitioning, purchasing, storing, and issuing of spare parts. 3. Arrangement Chapter is arranged as follows: Table of Contents Section - Introduction Section 2 - Manufacturer's Codes Section 3 - Parts List 4. Explanation of Parts List A. Contents The parts list contains a breakdown of the equipment into assemblies, subassemblies, and detail parts. All parts of the equipment are listed except: () Standard hardware items (attaching parts) such as nuts, screws, washers, etc., which are available commercially. (2) Bulk items such as wire, cable, sleeving, tubing, etc., which are also commercially available. (3) Permanently attached parts which lose their identity by being welded, soldered, riveted, etc., to other parts, weldments or assemblies. E. Parts List Form This form is divided into five columns. Beginning at the left side of the form and proceeding to the right, columns are identified as follows: April 25/83 l-- l- Page

43 () "Figure-Item Number" Column This column ists the figure number of the i llustration applicable to a particular parts list and also identifies each part in the list by an item number. These item numbers also appear on the illustration. Each item number on/the illustration is connected to the part to which it pertains by a leader line, Thus the figure and item numbering system ties the parts list to the illustrations and vice versa. (2) "Hobart Part Number" Column ALL part numbers appearing in this column are Hobart numbers. In all instances where the part is a purchased item, the vendor's identifying five-digit code and his part number will appear in the "Nomenclature" column. Vendor parts which are modified by Hobart will be identified as such in the "Nomenclature" column. In case Hobart does not have an identifying part number for a purchased part, the "Hobart Part Number" column will reflect "No Number" and the vendor's number will be shown in the "Nomenclature" column. Parts manufactured by Habart reflect no vendor code in the "Nomenclature" column. (3) "Nomenclature" Column The item identifying name appears in this column. The indenture method is used to indicate ttem relationship. Thus, components of an assembly are listed directly below the assembly and indented one space. Vendor codes and part numbers are shown in the column. Hobart modification to vendor items is also noted in this column. (4) "EFF" (Effective) Column This column is used to indicate the applicability of parts to different models of equipment. When more than one model of equipment is covered by a parts list, there are some parts which are used on only one model. This column is used forinsertion of a code letter "A", "B", etc., to indicate these parts and to identify the particuatar model they are used on. Parts in this manual are coded as follows: Uncoded parts are usable on all models. (5) "Units Per Assembly" Column This column indicates the quantity of parts required for an assembly or subassembly in which the part appears. This column does not necessarily reflect the total used in the complete end item. l-l Page 2 April-!%/83