A) Effectivity. This service bulletin applies to all BFS24 Battery and Charger systems

Transcription

1 Subject: Electrical Power Emergency Fuel Shut Off: Procedure for evaluation of battery condition and modifications to circuit to prevent unbalanced discharge. I. Planning Information A) Effectivity. This service bulletin applies to all BFS24 Battery and Charger systems 1) Boeing Part Numbers a) S283W008-1 Charger b) S283W008-2 Battery c) S283W008-3 Battery and Charger System 2) Radiant Part Numbers a) BFS24 Battery and Charger System b) 2313 Battery 3) Serial Numbers a) BFS24: 1408 and earlier b) 2313: 1566 and earlier This change applies to the components listed below: Part Number Name Used on BFS24 Battery and Charger System 777/ 737NG/ Battery Pack Assembly 777/ 737NG/ B) Reason. The reason for this service bulletin is that the Battery Health Feature in the electronics package (Boeing P/N S283W008-1) is such that, when the battery and charger are stored without power applied to the connector, one half of the battery discharges through a high resistance path inherent in the circuit. The other half is open circuit and does not discharge. Over a long period of storage, therefore, the state of charge of the two battery halves becomes significantly different and the normal recharging procedure will not restore the pack to full charge; the unit will not pass the ATP and cannot be installed in the aircraft. The procedure given in this service bulletin provides for: Page 1 of 9

2 1) Defining the batteries that have discharged to a level which will not allow recovery; these batteries must be scrapped and will be replaced by Radiant Power Corp. 2) Defining the batteries, which can be restored using the special recharging procedure given in this service bulletin. 3) Defining the rework of all battery packs to prevent further discharge mismatch during future storage. The rework procedure requires Radiant labels and parts for materials normally found in a maintenance facility. These items include: a).062 vinyl shrink tubing (3 ) b) Pin extractor p/n (AMP) c) Radiant label p/n 2341 d) Radiant label p/n 2342 e) Radiant label p/n 2343 The recharging procedure uses the standard test equipment normally required for performing maintenance in accordance with CMM If the inspections and rework defined in this service bulletin are not performed, the battery packs currently in storage will continue to discharge; eventually the entire maintenance stock of the BFS24 Battery and Charger System will become unusable and will have to be replaced. C) Description. The work required includes: 1) Sorting the battery packs between reworkable units and units which are no longer serviceable by measuring the voltage difference between the two halves of the battery. The status of the battery pack is then determined from the results of these measurements. 2) The recharging procedure consists of a continuous charge in the BFS24 Battery and Charger System on normal 28VDC power for 16 hours. Page 2 of 9

3 D) Approval. 3) The rework procedure consists of removing the center top lead from the battery pack and applying labels to the cover and battery pack defining changes to the product. The procedures and rework defined in this service bulletin do not affect fit, function or interchangeability of the BFS24 Battery and Charger system and therefore does not require FAA approval. Boeing performance approval is required. E) Manpower. It is estimated that the rework procedure will take one man-hour, and the recharging and sorting procedures will take two hours (this assumes one hour of monitoring during the 16 hours of charging). The estimated total time of three hours is required to complete all procedures (direct labor only). F) Material Cost and Availability. The materials required to accomplish the rework include.062 vinyl shrink tubing (3 ) and pin extractor (p/n ). These should be available in any maintenance facility. Radiant labels 2341, 2342, and 2343 are available through G) Tooling. The tooling required to perform normal maintenance in accordance with the CMM are all that are required to perform the inspections and rework required. H) Weight and Balance. - None I) Electrical Load Data. - Not affected. J) Software Accomplishment Summary. - Not applicable. K) References. 1) Other existing data: Component Maintenance Manual ) Process Data: None L) Publications Affected. Component Maintenance Manual will be revised to incorporate these procedures. Page 3 of 9

4 II. Accomplishment Instructions. A) Criteria for Battery Rework. Before accomplishing the battery rework described in the following paragraph, the battery must be checked in accordance with the following procedure: 1) Remove the BFS24 cover and disconnect and remove the battery per para. 3A & 3B (1) (2) & (3) page 302 of CMM ) With a DVM set to DC volts, measure the voltage first between the black wire and the orange wire, and then between the white wire and the orange wire. The following apply: Black/Orange Pin 7 /Pin 11 White/Orange Pin 12 / Pin 11 Two Halves Required Action 8.8VDC or less Any Value N/A Removed from service. Any value > 8.8VDC 8.8 to 16.5VDC Two halves vary > Charge 16 hours before 0.5VDC reworking the battery. Any value > 8.8VDC Any value > 8.8VDC Two halves the same Proceed directly with battery within 0.5VDC rework. B) Charging Procedure Prior to Battery Rework. 1) Reinstall the battery pack into the BFS24 per para. 4 (F) and (G) page 706 of CMM The cover need not be reinstalled for charging. 2) Connect the LRU to either the charging cable referred to on Page 7 Paragraph V or into the test setup defined by figure 101, page 104 of the CMM. Follow the procedure defined in para. 4A page 103 steps (1), (2), (5), (6) and (10) of the CMM to charge the unit with the test set. The LRU charging current will start in fast charge (560 to 840mA) and will reduce to trickle charge (68 to 102mA) within one hour. 3) Continue to charge at 68 to 102mA for 16 hours. Turn off system power supply E1 by opening SW11 on the test set. Disconnect the LRU from the test setup. 4) Remove the battery from the charger (per para. 1.a above) and again measure the voltage black to orange and white to orange. The two voltages should now be the same within 0.5VDC and each half should read 14.1VDC or greater. a) If the two half s are not within 0.5 VDC the battery will need to be discharged. To discharge the LRU on the test set, close SW7 and SW13 on the test set with SW1 off. Allow the battery to discharge until the total voltage Page 4 of 9

5 reaches 18VDC. Do not allow the voltage to go any lower or the battery pack will be ruined due to over-discharge. b) Once the 18VDC is reached then turn SW1 off, and allow the battery pack to cool for 30 minutes before charging. c) If after you cycle the battery through the discharge once and the battery meets the requirement of paragraph (II.B.4) continue with the battery rework in step (C), if not replace the battery. C) Battery Rework Procedure. Referring to Figure 2, accomplish the following operations: 1) With pin extractor p/n (AMP), remove the middle pin (orange wire) from the three-pin connector on the battery pack. 2) Extract white wire (with pin) from pin housing. Clip the orange wire 2 from the point where it emerges from the battery pack. 3) Cut a piece of.062 vinyl heat shrink tubing 3 long. Insert the heat shrink over the orange and white wire overlapping the orange wire 1.5. Using a heat gun, shrink the tubing over both wires. Note: Shield the Battery Pack to prevent heat damage to the pack 4) Insert the white wire back into the pin housing. D) Return to Service. 1) Affix the battery modification label (p/n 2343) to the battery pack to the left of the identification label. 2) Reassemble the battery pack into LRU following the procedure of para. 4 (F), (G) & (H) page 706 of CMM ) Conduct the performance tests described in para. 4 page 103 thru 107 of CMM Note: Since the battery has now been modified to remove the center connection, the battery health circuit will no longer function and all requirements to check health parameters (para. 4A (2), 4A (13) and 4B (11)) are deleted. Page 5 of 9

6 4) Affix labels 2341 & 2342 as shown in Figure 3. Be sure schematic on label lines up with silkscreen. 5) Complete the requirements of paragraph 5, page 707 of the CMM for packaging or storage. III. Material Information. The materials required to perform the rework defined in this service bulletin are considered to be As Required materials found in all aircraft maintenance facilities; therefore no repair kit information is required. Labels are available through Radiant Power Corp. IV. Warranty If after proper recharge of the battery pack the battery appears defective (under capacity) and battery is under warranty, return to manufacturer for evaluation and replacement. V. Setup of battery test and recharge. A) To charge with charging cable, apply 27.5VDC to the red banana plug (pin 5) with the return at the black banana plug (pin 6). B) To discharge the LRU with the charging cable, turn off system power supply. Turn on switch 1 (discharge switch) and allow the battery to discharge until it reaches a voltage of 18VDC. Do not allow the voltage to go any lower or the battery pack will be ruined due to over-discharge. As this discharge time is unknown you must watch the voltage closely or you may ruin the pack. C) Once the 18VDC is reached then turn SW1 off, and allow the battery pack to cool for 30 minutes before charging D) Parts needed for test procedure are as follows: 1) 30V, 1A power supply 2) 150 ohm, 30W Resistor 3) Terminal block with at least three connections 4) Connector MS24266R12B12SN * 5) One set of leads 6) One S283W008-1 Battery Charger 7) Wire 8) Switch with 30W rating Page 6 of 9

7 *NOTE: Aeroflite Enterprise, Inc. 261 Gemini Ave. Brea, CA (714) Figure 1: Charging Cable Page 7 of 9

8 Figure 2: Battery Rework Instructions Page 8 of 9

9 Parkland Dr. RADIANT POWER CORP. SARASOTA, FLORIDA BATTERY AND CHARGER SYSTEM BOEING PART NO. S283W008-3 RADIANT PART NO. BFS24 SUPPLIER SERIAL NO. CELL TYPE: NICKEL CADMIUM 600 mah AA WEIGHT: 40.0 OZ MAX. DATE CODE: TWO STAGE CHARGER EMI FILTER VDC INPUT 28VDC RETURN 10 HEALTH INDICATION 11 BATTERY SENSE FUSE SWITCHING & CIRCUIT PROTECTION JUMPER ON MATING CONNECTOR 22VDC OUTPUT 22VDC RETURN 15 AMP FUSE INSIDE STATUS INDICATION CHASSIS GROUND CAUTION THIS ASSEMBLY CONTAINS ELECTROSTATIC SENSITIVE DEVICES TWO STAGE CHARGER EMI FILTER FUSE SWITCHING & CIRCUIT PROTECTION 15 AMP FUSE INSIDE VDC INPUT 28VDC RETURN 10 HEALTH INDICATION 11 BATTERY SENSE 1 2 JUMPER ON MATING CONNECTOR 12 22VDC OUTPUT 7 22VDC RETURN 9 STATUS INDICATION 8 CHASSIS GROUND Figure 3: Label Locations Page 9 of 9