An American-Standard Company SERVICE MANUAL 4519 FN-27 FLASHER RELAY * * * * * * * * * * * * * * * * This manual contains information for shop repair, adjustment and calibration of FN-27 Flasher Relays with 2N-2R contacts. A detail parts list is included.,. March, 1977 C-77-250-713-3 UNION SWITCH & SIGNAL DIVISION WESTINGHOUSE AIR BRAKE COMRANY Swissvale, PA 15218
WABCCI ~ Section TABLE OF CONTENTS I GENERAL.... 3 A. Lamp Circuits, marking and capacity...... 3 B. Flashing Rate Stability......... 3 C. External Adjustment of Operating Rate.... 3 'II OILING OF PIVOTS.............. 3 '" ' ',',.. 111 ARMATURE..................................... 3. A. Cl~aning.............................. 3 B. Assembiy (End play, air gap, armature stroke, etc. ). 4 Sheet f. IV CONT ACT INSPECTION AND CLEANING........ 4 A. Burned or Pitted Contacts................ 4 B. Stack Insulation, damaged........... 4 C. Stack Screws............................ 4 D. Soldered Connections.............. 4 V CONTACT ADJUSTMENT.............. 5 A. Contact Identification......,...... 5 B. Lamp Contacts.... 6 C. Armature Bias........................... 6 D. Operating Contacts........... 7 E. Contact Position with Relay De-energized.... 8 F. Limping.... 8 VI FLASHING RA TE...,..................... 8 VII STARTING VOLTAGE............. 8 A. Correcting Failure to Start....... 8 VIII SER VICE RECOMMENDATIONS.............. 9 Calibration Table # 1............................ 9 IX PARTS LIST............ 11 4519, p. 2
I. GENERAL ' A. Lamp Circuits. Lamp contacts on the FN-27 flasher have binding posts marked ln- lh- lr and 2N-2H-2R. They may be used in circuits up to 26 volts to carry either d-c or a-c up to 2. 5 amps. When d-c lamp power is used, connect the positive (+) to lh or 2H binding post. The "Normal" lamp contacts, connected to posts IN and 2N, are closed when the relay operating circuit is de-energized. B. Flashing Rate Stability. The flashing rate does not vary with changes in operating voltage within its range. The relay is also temperature-compensated to provide a practically constant flashing rate over a wide range of temperature. C. External Adjustment of Flashing Rate. The flashing rate of the FN-27 may be changed, without opening the relay case, within the limits given on the calibration tag by manipulating a self-locking adjus~able magnetic shunt. To do this: (a) Remove seal wire and square nut; insert screwdriver. (b) Turn screw slowly, clockwise for slower rate, counter-clockwise fqr faster rate. (c) Replace nut and sealing wire. II. OILING OF PIVOTS It is recommended that Gulf Special Instrument Oil (U.S. & S. Reference UJ41099) should be used for oiling pivot screws. IT IS VERY IMPORTANT THAT THE OILING SHALL BE PERFORMED AS FOLLOWS: A. The bushing holes in the armature shall be perfectly clean and free from dust. B. The bearing area of the pivot screws shall be thoroughly covered with oil. The excess oil on the pivots shall be removed by just touching it with a clean lintless cloth. Care shall be taken not to cover the threaded portion of screws with oil. C. Care shall be taken that the oiled parts are protected from dust from the time of oiling until the relay is sealed. III. ARMATURE A. Cleaning. The armature should be removed for cleaning, before oiling, first marking the "front" edge (toward name plate) to aid in reassembling it correctly. The armature, including the.bushings and stop pins, should be thoroughly cleaned as well as the pole pieces and pivot screws. 4519, p. 3
WABCO ~ B. Assembly. (a) The armature should be located centrally between its brackets, and assembled with the same edge toward the front of the relay as before. (b) The end play of the armature along the pivot axis should not be less than 0.010" nor more than 0.015". (c) The pivot screws should be locked securely to the brackets. (d) The air gap at the middle pole piece should not be less than O. 005" with the pivot play taken up towards the pole piece. (e) The armature should be aligned with the main pole pieces (by shifting armature brackets if necessary) so that the air gap at each end is approximately uniform across its width when the stop pin is held against the pole piece by pressure applied between the pivots and the stop pin. The gap should not be less than O. 003" at any point across the width of the armature. (f) The armature stroke is factory-adjusted to a nominal O. 110" plus or minus 0. 010". To measure the stroke, (for use under Section V, "Armature Bias"), insert a spacer 0. 055" thick at one end of the armature between the main pole face and the armature stop pin, then exert slight pressure near that end of the armature to bring the stop pin against the spacer and also take up the pivot play. Measure the stop pin opening at the opposite end of the armature and add it to the 0. 055" spacer to find the total stroke. IV. CONTACT INSPECTION AND CLEANING A. Burned or pitted contacts should be smoothed with a contact cleaner (U.S. & S. Reference UJ39892) unless burned enough to require replacement. (Note: Mere discoloration or blackening of silver or silver alloy contacts does not indicate a need for cleaning. ) B. Stack Insulation that has been damaged by high voltage must be replaced. It is not permissible to use again any of the insulating spacers or bushings of a stack so damaged, because the carbonized material resulting from the arc may be spread on the surface of a new bushing during assembly and form a low-resistance path for another failure. For the same reason, the holes in each contact spring, stop, and terminal connector that is used again should first be thoroughly cleaned of all dirt and carhop.. C. Stack screws holding contact sections shall be checked for tightness and drawn down firmly. D. Soldered connections should be inspected to insure that each conductor is soldered to its terminal in such a manner that the solder forms a smooth surface over wire and terminal and fills the hole in the latter. Leads should be neatly dressed in such a way that they cannot interfere with moving parts of the relay. 4519, p. 4
--~ WABCCJ "-4""'- '/ V. CONTACT ADJUSTMENT 'Spacers used under the armature stop pins during contact adjustment are to be held firmly by pressure applied to the armature between the stop pin and pivots so as to bring the armature as close to the pole faces as play in the pivots will permit. The contacts should be adjusted in the order descriped, beginning with Section V-B. A. Contact Identification (See Fig. l, 2 and 3) NORMl!,L OPERATING CONTACT STOP NORMAL OPERATING CONTACT NORMAL OPERATING HEEL f'ig. 1 NORMAL OPERATING CONTACT NORMAL OPERATING HEEL!j,TOP REVERSE OPERATING HEEL 'l ; ~REVERSE OPERATING CONTACT.REVERSE OPERATING CONTACT STOP f'ig.2 REVERSE OPERATING CONTACT REVERSE LAMP CONTACT STOP REVERSE LAMP CONTACT LAMP CONTACT HEEL f'ig. 3 LAMP CONTACTS ORMAL LAMP CONTACT BUf'f'ER STOP (a) The operating contacts (with small double contact tips) are both at the same end of the relay. The one which closes when the armature goes to the pole piece at the operating contact end of the relay is called a "Normal" operating contact. The other closes when the armature goes to the pole piece at the opposite end and is called a "Reverse" operating contact. The Normal operating contact will be open when the relay is deenergized and the armature is at rest. It is very important that these contacts never be closed at the same time when energy is applied to the relay terminals. (b) The lamp contacts (with large single contact tips) are at the end of the relay opposite the operating contacts. Each has three spring members: the middle member has wedge-shaped contacts and is known as the "Heel"; the member farthest from the main pole piece acts with the "Heel" to form the "Normal" 4519, p. 5
WABCD ~ lamp contact (closed with armature at rest); the other member acts with the "Heel., to form the "Reverse" lamp contact. B. Lamp Contacts (See Fig. 3): These shall be adjusted by means of spacers under the stop pin at the lamp contact end of the relay. The contact should touch over at least 25% of the line contact between the silver alloy tips. (a) Normal Contacts 1. Adjust heel spring curled end to have - 1/4" I. D. 2. Adjust heel spring to be against armature insulation. 3. Adjust pressure at Normal contact of spring against its stop (heel not touching) - 10-15 gms. 4. Spacer to allow contact to close - O. 045". Same, if armature stroke is approximately 0. 100" - 0. 040". Same, if armature stroke is approximately 0. 120" - 0. 050". 5. Spacer for Normal contact to just touch its buffer stop should be 0. 030" plus spacer used to adjust Normal contact. (The buffer stop halts the movement of the Normal contact and its heel spring before the end of the armature stroke.) 6. Adjust heel pressure, with the armature at rest, so that each normal contact is compressed O. 015" minimum which should position the Normal contact spring either half-way between its stop and its buffer stop or closer to the buffer stop. 7. Re-check all Normal contact adjustments. (b) Reverse Contacts 1. Spacer to allow contact to close - 0. 025". 2. Spacer for light perceptible at contact - 0. 026". 3. Initial contact pressure against its stop - 10-15 gms. ( c) Safety Hook The hook on the end. of each lamp contact heel spring extending around the end of the insulation shall be adjusted by bending its tip so that light is just visible between it and the insulation when the armature is at the extreme limit of its movement in the normal direction; that is, the armature insulation should not touch the hook. C. Armature Bias After the lamp contacts and their heel springs have been adjusted, the bias of the arm.ature may be determined by measuring the "stop pin opening at the operating contact end with the relay de-energized and the armature at rest", referred to simply as "bias opening" in the following paragraphs. 4519 I P 6
WABCICI ~ If all adjustments have been made correctly the bias space will be O. 040" to 0. 050" varying with the armature stroke. Armature Stroke 0. 100" - 0. 110" 0. 110" - 0. 120" Bias Opening, Approx. 0.040" - 0.045" 0.045" - 0.050" Correct bias opening is essential to the satisfactory starting characteristics of the relay. If the bias opening is too large, the starting voltage will be too high. If the bias opening is too small, the armature may not be able to go to stop pin at the lamp contact end. In either case it will not be possible to adjust the operating contacts correctly. Incorrect bias opening is an indication that some part of the contact adjustment has been overlooked. The bias opening may be altered by a slight change in the heel pressure of the lamp contacts, but care must be taken to maintain enough heel pressure to compress the Normal contacts at least O. 015" as previously stated. relay. D. Operating Contacts less 0. 010". (a) Reverse Contact (See Fig. 2) 1. Use spacers under the stop pin at the operating contact end of the 2. Spacer to allow contact to close should be equal to bias _space 3. Initial contact pressure against its stop, 15-30 gms. approx. 4. With a 0. 050" to 0. 060" spacer, the heel should compress the reverse operating contact and just touch the armature. (If the relay fails to start readily at the slow operating rate, these values of contact pressure and heel pressure should be nearer the minimum. ) the relay. (b) Normal Contact (See Fig. 1) 1. Use spacers under the stop pin at the operating contact end of 2. Spacer to allow heel to just touch armature, approx. 0. 050". 3. Initial heel pressure against stop, approx. 25-40 gm. 4. Spacer to allow contact to close, Min. O. 015" 5. Bridging Opening, Min. 0. 015" Bias Opening Bias Opening Bias Opening 0.040" 0.045" 0.050" 0. 019" 0.016" 0.020" 0.020" 6. Initial contact pressure against its stop, approx. 15-25 gm. 7. Contact opening, armature away from heel, approx. 0."030". 4519 I p 7
WABCD ~ ~- Contact Position with Relay De-energized With the relay de-energizedand the armature freely at rest and all contacts correctly adjusted the reverse operating contact and the Normal lamp contacts will be closed and partly compressed. Re-check the bias opening to see that it has not changed appreciably. F. Limping If the armature operation is not regular, that is, if it "limps" holding one set of lamp contacts closed longer than the other, some correction can be afforded by increasing the pressure of the operating contact heel springs toward the armature insulation. This will not greatly affect the armature bias. If no limping is present to require such correction, and less heel spring pressure would be desirable for any reason, it may be decreased slightly. Limping may also be lessened by decreasing the pressure of the lamp contact heels, but this adjustment may change the armature bias and affect the setting of the operating contacts. VI. FLASHING RA TE The rate of flashing per lamp per minute can be checked over the full range of external adjustment by following the instructions given in Section 1-C. Screw the adjustable magnetic shunt all the way down (clockwise) to check the slowest possible rate of flashing and turn it as far as it will go in the opposite direction to check the fastest rate. These values should include the range shown on the calibration tag and will usually go somewhat beyond the maximum and minimum values shown. The check may be made at any voltage within the limits of normal voltage given in the Table, as the flashing rate does not vary with change in voltage. VII. STARTING VOLTAGE The relay shall be checked to.insure that it will start to operate at the minimum starting voltage given in the Table, or preferably at some lower value. A. Correcting Failure To Start (a) If the relay requires a starting voltage higher than the value specified in the Table, make the bias opening smaller (See Sect. V-C) by slightly increasing the pressure of the lamp contact heel springs. (b) If the relay starts at a low voltage but the armature fails to go all the way to the pole piece at the lamp contact end, make bias opening larger by slightly decreasing the pressure of the lamp contact heel springs, or by increasing the pressure of the heel spring of the Reverse operating contact. However, the correct Normal lamp contact compression with armature at rest must be maintained (See Sect. V-E). (c) If the relay armature attempts to start, as voltage is gradually increased from zero, but goes only far enough to close the Normal operating contact, then chatters there, correction can be made in one or more of the following ways: 4519 I P 8
Increase the pressure of the heel spring of the Normal operating contact against its stop. Make the bias opening slightly larger. Re-adjust the Normal operating contact spring, using a spacer 0. 001" or 0. 002" thinner than that specified in Sect. V-B. VIII. SERVICE RECOMMENDATIONS It is recommended that the FN-27 relays be removed from service and shopped if the starting voltage becomes -higher than the Minimum Operating Volts or if the flasher action is objectionably irregular. Because of the special fixtures involved we recommend that a relay be returned to the factory for replacement of a coil, pole piece or core. TABLE #1 2N-2R Contacts Relay Range Starting Resistance Operating Volts Flashes per Lamp Volts Ohms Normal Minimum per Minute Minimum 85-85 10-20 8.0 52-60 7. 5. 35-35 6-8 4.8 52-60 4.5 4519, P~ 9
WABCD ~ 16 16 51 47 26 39 7 47 ~8 42 23 23 18 18 17 Figure 1. FN-27 Flasher Relay 4519, p. lo
WABCO "'411ti,,'V' IX. DE'l'AIL PARTS LIST, REFER TO FIGURE 1, FN-27 FLASHER RELAY Parts common to all FN -27 Relays are indicated in the "Used On" column by the word "". Indented item descriptions indicate that the references in the "Used onn column refer to this parts list. Order By Reference, Piece, and Abbreviated Description REF. PIECE DESCRIPTION DRAWING USED ON.. 2 UN280143 3 UN280142 4 UN280144 5 UN280145 6 UJ52446 7 UJ47801 8 UM152720 9 UJ78298 10 UM160279 11 UJ78167 12 UM215372 13 UM152726 14 UM246798 15 UN280157 Contact Section, Complete (stack section HB) Bl2660-50 Contact Section, Complete (stack section HA). B12660-50 Contact Section, Complete (stack section HC) B12660-50 Contact Section, Complete (stack section HD) Bl2660-50 Screw, Mach 3-56 x 1-1/16 Washer, Lock No. 3. Plate.... 7828-275. Insulation............. 8750-1460 Insulation Bushings, B10266-l. ltlsulation............. 8750-2503 Terminal Connectors 8244-142 Contact Spring stops 8385-2166 Contact Spring Stops 8385-2345 Contact Spring, Complete 8385-2802 2, 3 2,3 2,3 4,5 2,3 2,3 16 17 18 UN280156 UN221763 UN221765 19 UJ78121 20 UJ78353 21 UJ52298 22 UM239758 23 UM280153 24 UJ52403 25 UM239759 26 UN280159 27 UM280132 28 UM115706 29 UJ47818 30 UM127260 Contact Spring, Complete 8385-2883 Contact Spring, Complete... 8385-2703 Contact Spring, Complete 8385-2704 Insulation 8750-3044. Insulation.................... 8750-1460 Screw, Mach Fil. hd. 3-56 x 1 Insulation Bushing B10266-1 Terminal Connector 8244-142 Screw, Mach, Fil. hd. 3-56 x 7 /8 Insulation Bushing B10266-l Coil, 85 ohms Complete,,,, 8133-657 Plate, Top............................. C16942-l Post, Binding 8094-1192 Washer o 7828-139 Nut....................... 8109-194 2,3 4,5 4,5 2,3,5 4 4 4,5 5 5 31 UM159677 Nut, Seal............. 8109-453. 4519, p. 11
REF. PIECE DESCRIPTION DRAWING USED ON ' 32 UM280135 33 UM252217 34 UJ47429 35 UN280138 36 UM280137 37 UM288972 38 UM280133 39 UM280683 40 UN280682 41 UN280147 42 UM18757 43 UM162010 44 UM280152 45 UM535 46 UN280151 47 UM283491 48 UM175630 49 UM283450 50 UJ47427 51 UJ53011 52 UM258824 53 UJ47248 54 UJ630219 55 UJ780234 56 UM117 93 57 UJ52353 58 UJ52130 59 UJ52089 60 UJ47715 61 UJ52538 62 UJ47714 63 UJ52620 64 UN280687 65 UM29101 66 UM142777 67 UM280684 68 UJ52092 69 UJ47733 70 UJ48172 4519 I P 12 Bushing.............. Nut..., Gasket Support, Shunt Complete Support......... Nut o Shunt.............. Pole Piece.... Bracket, Armature...... Core........... Washer.... Screw............. Screw, Pivot... o Nut. Armature, Complete...... Ferrule o Washer Washer.. o Gasket o Caseo. o o o Washer Washer... 0 Nameplate.. Shim... o Washer... o o o Screw, Fil. hd. 10-32 x 1 steel Screw, Flat hd. 10-32 x 3/4 steel Screw, Flat hd. 10-32 x 1-5/8 steel Washer, Lock No. 10 steel Screw, Rd. hd. 8-36 x 3/4 steel, Washer, Lock No. 8 steel Screw, Rd. hd. 4-40 x 1/2 steel Shock Absorber....... Nut, Binding...... c o o o Tag (Order should specify marking desired), Bracket (For Wall Mounting) Screw, Mach Flat hd. steel 10-32 x 5/8 (Tin Pl.) Washer, Lock No. 10 (Tin Pl.) Nut, Hex. steel 10-32 (Tin Pl.) 8350-1089 8265-395 8078-1512 8350-1090 8350-1090 35 8109-311 35 8250-141 8250-145 8303-144 8101-424 7828-104 8098-1300 8378-375 8109-1 8157-521 8350-752 7828-374 8486-432 8078-1818 C 16942-2 7826-329 80780-1407 8225-1018 12775-29 7828-218 12404-27 8109-193 8988-75 10914-342