Section II. TOOLS AND EQUIPMENT

TM 11-6125-259-30

ar. Set UNIT PWR switch S6 to ON position and

between 393 and 407 Hz.

al. Set 200% RATED LOAD CURRENT switch

apply 26 vdc input from the input power supply.

S1 to the down (off) position.

as. Set the OUTPUT MONITOR swith S16 to A

position and SHORT swith S10 to the up(on)

am. set PHASE CURRENT switch S11 and

OUTPUT MONITOR switch S16 to C position.

position.

at. Before A output currant foldback (digital

an. Bfore C output foldback (digital

voltmeter No. 3 reads 100 mV or less), read the

voltmeter No. 3 reads 100 mV or less), measure the

output current equivalent millivolts (100 mV = 1

following C parameters. (The output current

amp) as indicated on digital voltmeter No. 3. The

foldback occurs in 5 to 15 seconds after switch S1 is

output current shall be 5.43 amps or greater.

set to 200% RATED LOAD position. If necessary,

reset output overload condition to enable

au. set the OUTPUT MONITOR switch S16 to B

Position, SHORT switch S10 to the down (off)

measurement of listed parameters.)

position and S20 to the up (on) position.

(1) Read Output voltage as indicated on digital

av. Before B output current foldback (digital

voltmeter No. 4 The output voltage shall be 50

voltmeter No. 3 reads 100 mV or less), read the

vrms or less.

output current equivalent millivolts , (100 mV = 1

(2) Read the output current equivalent

millivolts (100 mV = 1 amp) as indicated on digital

amp) as indicated on digital voltmeter No. 3. The

output current shall be 5.43 amps or greater.

voltmeter No. 3. The output current shall be 4.34

amps or greater.

aw. Set the OUTPUT MONITOR switch S16 to C

position, SHORT switch S20 to the down (off)

(3) Read the output frequency as indicated on

electronic counter. The output frequecy shall be

position and S30 to the up(on) position.

between 393 and 407 Hz.

ax. Before C output current foldback (digital

ao. Set 200% RATED LOAD CURRENT switch

voltmeter No. 3 ready 100 mV or less), read the

S1 to the down (off) position and set UNIT PWR

output current equivalent millivolts (100 mV = 1

switch S6 to OFF position.

amp) as indicated on digital voltmeter No. 3 The

ap. Set switches S2, 3, 4, 12, 14, 22, 23 and 24 to

output current shall be 5.43 amp or greater.

the down (off) position.

ay. Set UNIT PWR switch S6 to OFF position,

aq. Set switches S7, 8, 9, 17, 18, 19, 27, 28 and 29

deenergize input power supply and remove unit

to the up (on) position (250 VA, 0.75 P.F. Load).

from test setup.

Section II. TOOLS AND EQUIPMENT

3-7. Tools and Equipment

b. DC Power supply, any commercial type

providing 0 to 40 vdc, 50 amps maximum.

The following instruments or equivalent are

c. Oscilloscope AN/USM-281

required to perform the inverter operational

d. Digital Voltmeter AN/GSM-64

checkout:

e. Electronic Counter AN/USM-207

a. Dc power supply, any commercial type

f. Distortion Analyzer TS-723/A

providing 0 to 45 vdc, 6 amps maximum.

g. EM1289A Test Fixture, Gulton No. 421773

Section Ill. TROUBLESHOOTING

3-8. Troubleshooting

component part. Note that initial digit of the part

number is also the module number. For example,

Use table 3-2 to troubleshoot the inverter to the

transistor Q206 is a component of the A2 module.

module level or to the component part level. Then

Refer to paragraphs 3-9 and 3-10 for information

replace either entire defective module or defective

on complete disassembly/assembly of inverter.

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