R Continuity Test - Ohmmeter Check Figure 001
20-52-21 Page 2
(2) For circuits with conductors connected via standard electrical control components (switches, pushbuttons, etc...):
-
in static mode (without operation of the control components) I less than or equal to 0.5 A with U = 10 VDC max.
-
in dynamic mode (with operation of the control components) P less than or equal to 100 mVA with U = 10 VDC max.
_________
4. Procedure
(Ref. Fig. 002)
_______
CAUTION : DO NOT CAUSE DAMAGE TO CONNECTOR CONTACTS WHEN YOU DO CONTINUITY CHECKS. DAMAGED CONTACTS CAN BECOME LOOSE AND CAN THUS INTERMITTENTLY PREVENT CORRECT CONTINUITY.
_______
CAUTION : BE CAREFUL NOT TO CAUSE DAMAGE TO THE WIRE INSULATION. IF THERE IS DAMAGE TO THE INSULATION, MOISTURE CAN GO INTO THE WIRE AND CAUSE CORROSION AND SUBSEQUENT FAILURE OF THE WIRE.
A. Test of the Continuity of an Aircraft Wire
There are two methods for this test:
(1) Continuity test with aircraft wire connected to a grounding point (Ref. Fig. 002)
(a)
Disconnect the aircraft wire at the two ends.
(b)
Connect one end of the aircraft wire to a grounding point.
R (c) Connect one of the ohmmeter probes to the other end of the wire.
R (d) Connect the second ohmmeter probe to a grounding point.
(e) Make sure that the current flows through the conductor (the indication on the ohmmeter changes).
____
NOTE : The resistance value of the wire is shown. For calculation of the normal resistance value, refer to the Standard Manual (resistance per metre).
____
NOTE : We recommend that you do a short circuit detection test after this procedure. This is to make sure that there is no short-circuit to the structure before a possible continuity defect.
20-52-21 Page 3
R Continuity Test Figure 002
20-52-21 Page 420-52-21 Page 5
(2) Continuity test with an extension wire:
(a) Disconnect the aircraft wire at the two ends.
(b) Connect the extension wire to one end of the aircraf wire.
R (c) Connect the extension wire to one probe of the ohmmeter.
R R (d) Connect the second ommeter probe to the second end of the aircraft wire.
(e) Make sure that the current flows through the conductor (the indication on the ohmmeter changes).
____NOTE : The resistance value of the wire is shown. For calculation of the normal resistance value, refer to the Standard Manual (resistance per metre).
____NOTE : We recommend you that you do an insulation test after this procedure.
__________________________________________________
TEST FOR SHORT CIRCUIT - DESCRIPTION AND OPERATION
__________________1. Reason for the Job
_______WARNING : BE CAREFUL WHEN YOU USE ELECTRIC TOOLS IN AREAS WHERE THERE ARE RISKS OF EXPLOSION (FUEL TANKS, FUEL VAPOUR AREAS, ETC.). REFER TO YOUR LOCAL REGULATIONS AND MAKE SURE THAT YOU OBEY THEM. SOME ELECTRIC TOOLS SUCH AS HEAT GUNS, SOLDERING IRONS AND TOOLS WITHOUT INTRINSIC PROTECTION ARE NOT PERMITTED IN THESE AREAS.
The following procedure does not replace trouble shooting. It only gives general test method to be applied on aircraft.
______________________2. Job Set-Up Information
A. Fixture, Tools, Test and Support Equipment
R ------------------------------------------------------------------REFERENCE QTY DESIGNATION ------------------------------------------------------------------No Specific Ohmmeter
R R ____NOTE : For a test for a short circuit in the fuel tanks, use an intrinsic safety ohmmeter (For example: Ohmmeter CULTON type 278, AVTRON T477W or equivalent)
__________3. Job Set-Up
R A. Ohmmeter Check
R R (1) Before you start the test for a short circuit , make sure that the ohmmeter operates correctly. (Ref. Fig. 001)
R (2) With the two probes in contact adjust the ohmmeter to show zero Ohm.
B. Voltage and Current Values for the Test. Use these voltage values:
(1) For circuits with conductors connected directly via standard electrical connections (connectors, modules, etc ...): - 0.1 A less than or equal to I less than or equal to 2 A with U = 28 VDC max
20-52-22 Page 1
R Check for Short Circuit - Ohmmeter Check Figure 001
20-52-22 Page 220-52-22 Page 3
(2) For circuits with conductors connected via standard electrical control components (switches, pushbuttons, etc...): - in static mode (without operation of the control components) I less than or equal to 0.5 A with U = 10 VDC max. - in dynamic mode (with operation of the control components) P less then or equal to 100 mVA with U = 10 VDC max. 中國航空網 www.k6050.com 航空翻譯 www.aviation.cn 本文鏈接地址：A320 ESPM Electrical Standard Practices Manual 4(67)
