Table 2-1. Direct Support Troubleshooting Guide (Continued)
TEST OR INSPECTION
(c) Replace switch PB3 if either side is open (para. 2-22).
(d) Replace transformer T1 if all the above checks have not solved problem (para. 2-25).
4. ROWPU utility circuits do not work. (Ref. Schematic diagram FO-1, sheet 5, schematic lines 529-537).
Check generator voltage. It must be 435-440 VAC on all three phases.
(a) Adjust to correct voltage.
(b) If voltage cannot be adjusted to correct voltage, refer to generator troubleshooting.
Shut down ROWPU and generator. Refer to electrical drawings in Appendix D and remove the H1, H2, X1 and
X2 wires from transformer T2 (REF: Interconnection diagram FO-2, Sheet 10). Check continuity, point-to-
point, from the power distribution block (PDB) (REF: Interconnection diagram FO-2, Sheet 10) to transformer
T2, wires AL2 to T2(H1) and AL3 to T2(H2).
(a) Repair any loose or damaged wire (para. 2-20).
(b) Replace circuit breaker CB16 (REF: Interconnection diagram FO-2, Sheet 10) if it is open on either
phase (para. 2-25).
Check continuity, point-to-point, from T2(X1) to CB13 (REF: Interconnection diagram FO-2, Sheet 8) and to
relay K27(A2X) (REF: Interconnection diagram FO-2, Sheet 8). Repeat the procedure from T2(X2) to
terminals 1-84 and 1-82.
(a) Repair any loose or damaged wires (para. 2-20).
(b) Replace transformer T2 if all the above checks do not solve problem (para. 2-25).
1. Flowmeter(s) do not show any flow. (Ref. schematic diagram FO-1, sheet 8, schematic lines 815-819).
Shut down the ROWPU. Open the control panel door and then power up the panel. Check the power supply
PS1 (REF: Interconnection diagram FO-2, Sheet 8) for 110-120 VAC power on the input side.
If the voltage is correct, go to step 3.
Shut down ROWPU and generator. Refer to electrical drawings in Appendix D. Check continuity, point-to-
point, from circuit breaker CB9 (REF Interconnection diagram FO-2, Sheet 8) to PSI (wire #264). Repeat the
procedure from transformer T1(X2) (REF: Interconnection diagram FO-2, Sheet 10) to PS1 (wire #2A).
Remove wire #2A from PS1 during testing.
Repair any loose or damaged wire (para. 2-20).
Check PS1 output for 12 VDC.
Replace PSI if the output voltage is less than 11.5 VDC (para. 2-23).
Check the flowmeter(s) that is inoperative for 12 VDC on the flowmeter voltage input terminals.
If voltage is not present, replace/repair the wires from PSI + - terminals on the flowmeter (para. 2-20).
Remove the flow sensor for the inoperative meter from the piping. The feed flow sensor is located on t he front
wall piping, the waste sensor is located on the ceiling next to the control panel, and the product sensor is on
the back wall piping behind the control panel. Check the paddle wheel for debris and ease of rotation.
(a) Use a stiff brush and remove any debris that may be sticking to the wheel.
(b) if the paddle wheel cannot be cleaned up so that it spins very easily, replace it (para. 2-18).
Disconnect the black and red low sensor leads at the flowmeter and attach a multimeter to them. Set the
meter to the 0-1 VAC scale. Spin the paddle wheel vigorously and watch the multimeter. The needle should
show a voltage reading.
(a) If the meter does not indicate voltage, replace the flow sensor (para. 2-18).
(b) Return the ROWPU to service and check the flowmeter for operation.
If the flowmeter still does not work, replace it and adjust the new flowmeter (para. 2-22).