Trane RTWA 70-125 TON - Manual (Page 63)

RLC-SVD03A-EN 63
Module Power and Miscellaneous I/O
3. Check the resistance from each of the three phase pins (J4-3, J4-2, and
J4-1) to the board edge GND, with the connector unplugged. This resis-
tance should be between 100K and 200K ohms.
If the valve/wiring/connector combination fails the above tests, suspect the
connector or the wiring first. At the valve for circuit #1; wire color black corre-
sponds to pin #5, red to pin #3, white to #2 and green to #1. For circuit #2:
black to pin #6, red to pin #4, white to #2, and green to pin #1. Refer to
Table
20 and use the pass-fail results above to determine the prescribed action.
SEHI EXV Valve Winding Resistance Check
1. Disconnect the appropriate EXV valve from the pin header of the EXV
module.
2. With a digital ohm-meter, check the resistance of the valve windings and
associated leads/connector by measuring the resistance of pin pairs at
the connector plug. Pin pairs are #5 and #4, #2 and #1 for Circuit 1 and #6
and #5, and #2 and # 1 for Circuit 2. Pin numbers are indicated by corre-
sponding position # on the board or by the raised numbers of the connec-
tor block. The resistances should all be 75 ohms ±10 ohms.
3. Check the resistance from each lead to the board edge GND, with the
connector unplugged. This resistance should be greater than 1 meg
ohms.
If the valve/wiring/connector combination fails the above tests, suspect the
connector or the wiring first. At the valve for circuit #1; wire color black corre-
sponds to pin #1, red to pin #5, white to #2 and green to #4. For circuit #2:
black to pin #1, red to pin #6, white to #2, and green to pin #5. Refer to
Table
20 and use the pass-fail results above to determine the prescribed action.
Solder Techniques for Installation
It is not necessary to disassemble the valve when soldering to the
connecting lines. Most commonly used types of solder (eg. Sil-Fos, Easy-
Flow, PhosCopper or equivalent) are satisfactory. Regardless of the solder
Table 20 Test Results Logic Table
ELECT. INTEGRITY TEST
* STROKE TIMING RESISTANCE PRESCRIBED ACTION
PASS PASS NOT REQ. VALVE/BOARD ARE WORKING PROPERLY -
NO ACTION REQ.
PASS FAIL PASS VALVE IS MECHANICALLY STUCK -
REPLACE/REPAIR VALVE
PASS FAIL FAIL HIGHLY UNLIKELY CONDITION
RETEST-REPLACE MODULE
FAIL PASS PASS HIGHLY UNLIKELY CONDITION
RETEST-NO ACTION REQ.
FAIL FAIL PASS CHECK CONNECTION AT MODULE
RETEST-REPLACE MODULE
FAIL FAIL FAIL SUSPECT WIRING, PLUG OR VALVE-
REPLACE/REPAIR SAME
*.INDICATION OF PASS OR FAIL OF THIS TEST IS DISPLAYED AT THE CLD IN THE DIAGNOSTICS MENU.