Thermal Dynamics MERLIN 6000, Руководство по обслуживанию, Страница: 37 / 112

Manual 0-2569 31 SERVICE TROUBLESHOOTING
coolant flow indicator is not lit, replace the LED
PC board. If J3-2 measures greater than +12 vdc,
replace the Logic PC Board.
J. Coolant Conductivity Circuit
The conductivity probe consists of two insulated pins that
extend into the coolant reservoir. The Logic PC Board
sends out an AC voltage level on J2-24 that varies with
the conductivity of the coolant.
1. Disconnect one of the wires to the conductivity
probe (wire #57 or 58). The Logic PC Board will
see infinite resistance and the coolant conductiv-
ity LED indicator should be ON. If the coolant
conductivity indicator is ON, replace the coolant
(refer to Section 4.02-F). If the problem remains
after coolant is changed, replace the conductivity
probe.
2. If the coolant conductivity indicator is not lit with
the probe disconnected, measure between the
Logic PC Board common (TP1) and J3-1. If the
voltage measures below +12 vdc, replace the LED
PC board. If the voltage measures above +12 vdc,
replace the Logic PC Board.
K. Power Supply Start Circuit
NOTE
Refer to Appendix XI for Start Circuit Diagram.
The following describes the flow of the START signal
through the system.
• The START signal enters the Master Power Supply
at J15-24 (sig) and J15-25 (return). This is in paral-
lel with TB2-3 and TB2-4 which can be used in-
stead of J15.
• From J15 or TB2 the signal goes to the Logic PCB at
J1-19 and J1-18. This turns ON the START LED
(D8). • After pre-flow and at the same time that
the Master Power Supply Main Contactor (W)
comes ON, the START TO SLAVE signal leaves the
Master Power Supply Logic PCB at J4-6 and J4-5.
• The signal then goes through the Isolation PCB and
Parallel Cable to the Slave Power Supply J15-24
and J15-25.
• Inside the Slave Power Supply the signal contiues
to Logic PCB at J1-19 and J1-18, turning ON the
Slave Power Supply START LED (D18).
• If the Master Power Supply starts but the Slave
Power Supply does not get a START signal (START
LED is OFF) refer to Section 4.05-T, Isolation PCB
and Parallel Cable Interface.
• If the START LED is ON, even momentarily, go to
Section 4.05-N, Main Contactor (W) Control Cir-
cuit.
Start problems could be either in the Master Power Sup-
ply or the remote control circuits. To isolate the faulty
area do the following:
1. Remove the Remote Cable from Master Power Supply
J15 or the connections from TB2 (or both).
2. Install a jumper from TB2-1 to TB2-2 to enable the
Master Power Supply.
3. Turn on the power.
4. Wait 40 seconds for the power on purge.
5. Apply a START signal by jumping TB2-3 to TB2-4.
• If the Master Power Supply starts, the problem is in
the remote circuits, refer to Section 4.05-L, Remote
Start Circuit.
• If the Master Power Supply did not start do the
following:
Check the Master Power Supply Front Panel indi-
cators for normal conditions. The TEMP LED
should be green and the COOLANT PRESSURE
LED should be ON. Next, on the Master and Slave
Power Supply Logic PC Boards, check the READY
(D6) and RUN (D7) LEDs. Both should be ON. In
the Slave Power Supply, the LEDs should be ON
right after power is applied.
• If the front panel indications are normal, but the
READY LED on the Logic PCB is OFF, the Power
Supply Logic PCB is faulty.
• If the TEMP LED is red or the COOLANT PRES-
SURE LED is OFF, refer to Sections 4.04-G and
4.04-J.
• If the READY LED is ON and the RUN indicator is
OFF do the following:
Make sure the RUN/SET Switch is in RUN posi-
tion.
Check for nearly 0 vdc on the Logic PCB from TP1
(ground) to J1-13, front panel RUN.
• If voltage is correct, then the Logic PCB is faulty.
• If Slave Power Supply does not start do the follow-
ing:
The Slave Power Supply has no coolant and re-
quires the THIS IS SLAVE signal to disable the
coolant input. A jumper in the Parallel Cable from
J15-35 to J15-36 provides the THIS IS SLAVE sig-