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DimaVLad
22-05-2023, 07:20 AM
Hello, i have a problem with a Carrier 30RB flow sensor error (P14 Water flow control and customer interlock fault). I replaced the sensor with a new one but same P14 error, i measured the voltage and the sensor voltage output its 24 vac instead of 12vac (When unit flow rate is above the minimum flow rate, then the output is switched on, sending 24 vac through a 560-ohm dropping resistor. This provides 12 vac to the MBB to prove flow has been established). The pump it's running, pressure it's ok and the flow it's present since i hear the water flowing and if i try to close a valve the pressure rises). The resistor it's ok 560 ohm, i replaced the main board with one from a functional chiller but the same P14. There is no customer interlock and if i plug or unplug the sensor the error it's the same.
I have the documentation and i saw that it's connected in series the pump interlock, but i don't have a pump interlock. Thank you!

P.14 — Cooler Interlock Failure
Criteria for Trip — The criteria are tested whether the unit is
ON or OFF. This algorithm monitors the cooler flow switch
circuit, which may include field-installed cooler pump
interlock (PMPI) contacts. The pump interlock and flow
switch are wired in series, therefore either device can cause a
MC
ERROR
CODE
MASTER SLAVE DESCRIPTION
01 X X The master or slave water pump is not configured while the control of the lag unit pump is required
(lag_pump = 1)
02 X Master and slave units have the same network address.
03 X There is no slave configured at the slave address
04 X Slave pump_seq incorrect configuration
05 X There is a conflict between the master and the slave LWT option: the master is configured for EWT control
while the slave is configured for LWT control.
06 X There is a conflict between the master and the slave LWT option: the master is configured for LWT control
while the slave is configured for EWT control.
07 X There is a conflict between the master and the slave pump option: the master is configured for lag pump
control while the slave is not configured for lag pump control.
08 X There is a conflict between the master and the slave pump option: the master is not configured for lag pump
control while the slave is configured for lag pump control.
09 X X The slave chiller is in local or remote control (chilstat = 3)
10 X X The slave chiller is down due to fault (chilstat = 5)
11 X The master chiller operating type is not Master: master_oper_typ and master_status = off
12 X X No communication with slave.
13 X Master and slave heat/cool status are not the same.
EWT — Entering Water Temperature
LWT — Leaving Water Temperature
75
cooler interlock failure. This alarm is generated if one of the
following criteria is met:
1. The circuit (flow switch and optional pump interlock installed
at TB5-1 and 2) fails to close within the OFF to
ON delay (ConfigurationOPTNDELY).
2. If the unit is the lag chiller under Master/Slave Control
and the circuit fails to close within 1 minute after its
pump is commanded ON.
3. The circuit opens while the machine is ON.
4. If the remote interlock switch is CLOSED while the
machine is ON (units with EMM only).
5. If the machine is configured for Cooler Pump Control
and the circuit does not open within 2 minutes.
6. The circuit fails to close within the OFF to ON delay
when the cooler pump has been commanded ON for
freeze protection

seanf
22-05-2023, 07:12 PM
Is the signal getting to the board?
Are you able use a jumper wire to test the correct operation of the board?

DimaVLad
24-05-2023, 01:37 PM
Hello, i solved it thank you for the replay. It was a wiring problem due to a bended pin on the MBB exactly at the pump interlock option were the loop wire was connected. However i hit another problem because the compressor it's broken. I attached a edited image to be under 100 KB, sorry for the bad quality 16237