Operating instructions

99
• power supply to the pump
• control signal to the pump controller
• chilled water pump operation
• cooler pump contactor for proper operation
Alarm 66 — Electrical Box Thermostat Failure/Reverse
Rotation (P.28)
Criteria for Trip — The alarm criteria are checked whether the
unit is ON or OFF. If channel 15A on the MBB, which is used
for field wired external pump interlock, is open then the alarm
will be generated.
Action to be Taken — Unit shut down or note allowed to start.
Reset Method — Automatic, if the channel is closed, the unit
will start normally.
Possible Causes — If this condition is encountered, check the
following items:
• jumper wiring on TB5-1 and TB5-2 when channel is not in
use
• external pump status
• field wiring for the external pump interlock
Alarm 67 — Loss of Communication with System Manager
(P.29)
Criteria for Trip — The criterion is tested whether the unit is
ON or OFF. This alarm is generated if the System Manager
had established communications with the machine and is then
lost for more than 2 minutes.
Action to be Taken — The action to be taken by the control
depends on the configuration. If Auto Start when SM lost is
enabled, (Cooler Heater Delta Spt, AU.SM=YES), then the
unit will force the CCN Chiller Start Stop to ENBL and clear
all forced points from the System Manager. The unit will revert
to stand-alone operation.
Reset Method — Automatic, once communication is
re-established.
Possible Causes — If this condition is encountered, check the
following items:
• communication wiring
• power supply to the System Manager and unit controls
Alarm 68 — Master/Slave Communication Failure (P.30)
Criteria for Trip — The criterion is tested whether the units are
ON or OFF and a master and slave machine has been config-
ured, (Master/Slave Select, MSSL=1 and Master/Slave
Select, MSSL=2). If communication is lost for more than 3
minutes, this alarm is generated.
Action to be Taken — Dual chiller control will be disabled and
each unit will operate in Stand-Alone mode.
Reset Method — Automatic, once communication is
re-established.
Possible Causes — If this condition is encountered, check the
following items:
•CCN wiring
• control power to each Main Base Board, master and slave
• confirm correct configuration
Low Oil Pressure
Alarm 69 — Circuit A (P.67)
Alarm 70 — Circuit B (P.68)
Alarm 71 — Circuit C (P.69)
Criteria for Trip — The criteria are tested only when the com-
pressor is ON. The alarm is generated if one of the following
occurs, where:
oil = oil pressure transducer reading for the appropriate com-
pressor
sp = suction pressure reading for the affected circuit
dp = discharge pressure reading for the affected circuit
oil_sp1 = 0.7 x (dp-sp) + sp
oil_sp2 = sp + 7.2 psi (15 seconds after start)
oil_sp2 = sp + 14.5 psi (45 seconds after start)
If the compressor starts with the ambient temperature (OAT
less than 36° F [2° C] the oil pressure monitoring is delayed by
30 seconds.
Action to be Taken — The affected compressor will be
stopped. The other compressors will continue to operate.
Reset Method — Manual.
Possible Causes — If this condition is encountered, check the
following items:
• sensor wiring to the CPM Board
• board for a faulty channel
• faulty transducer
• plugged oil filter
• faulty oil solenoid valve coil
• stuck oil solenoid valve
• stuck check valve
• manual shut off valve to ensure it is fully open
• confirm unit configuration
Max Oil Filter Differential Pressure Failure
Alarm 72 — Circuit A (P.70)
Alarm 73 — Circuit B (P.71)
Alarm 74 — Circuit C (P.72)
Criteria for Trip — The criterion is tested when the compres-
sor has been operating for at least 5 seconds. The alarm is
generated if the difference between the Circuit Discharge Pres-
sure and the Compressor Oil Pressure is greater than 50 psi
(345 kPa) for more than 30 seconds.
Action to be Taken — The affected compressor will be turned
off.
Reset Method — Manual
Possible Causes — If this condition is encountered, check the
following items:
• check the discharge and oil sensor wiring to the Main Base
Board and CPM board
• boards for a faulty channel
• faulty transducer
• plugged oil filter
• faulty oil solenoid valve coil
• stuck oil solenoid valve
• stuck check valve
• manual shut off valve to ensure it is fully open
Check the power supply to the System Manager and unit
controls.
High Oil Filter Pressure Drop
Alarm 75 — Circuit A (P.84)
Alarm 76 — Circuit B (P.85)
Alarm 77 — Circuit C (P.86)
Criteria for Trip — The criterion is tested when the compres-
sor has been operating for at least 5 seconds. The alarm is gen-
erated if the difference between the Circuit Discharge Pressure
and the Compressor Oil Pressure is greater than 30 psi for
more than 5 minutes.
Action to be Taken — The compressor will continue to run.
Reset Method — Manual
Possible Causes — If this condition is encountered, check the
following items:
• discharge and oil sensor wiring to the Main Base Board and
CPM board
• boards for a faulty channel
• faulty transducer
• plugged oil filter
• faulty oil solenoid valve coil
• oil solenoid valve stuck open
• stuck check valve
• manual shut off valve to ensure it is fully open