Johnson Controls DMS 360 Series, Инструкция по установке, эксплуатации и обслуживанию

Страница: 24 / 28

Installation, Operation and Maintenance Manual : 036-1011(0806) Page 23
9. If 24 volts is present at the UCB Y2 terminal and none of
the switches are open and the compressor is not locked
out, the UCB may have the compressor in an ASCD.
Check the LED for an indication of an ASCD cycle. The
ASCD should time out within 5 minutes. Press and
release the TEST button to reset all ASCDs.
10. The UCB can be programmed to lock out compressor
operation during free cooling and in low ambient
conditions. These options are not enabled by default.
Local distributors can test the UCB for this programming.
11. If none of the above corrected the error, test the integrity
of the UCB. Disconnect the C2 terminal wire and jumper
it to the Y2 terminal. DO NOT jump the Y2 to C2
terminals. If the compressor engages, the UCB has
faulted.
12. If none of the above correct the error, replace the UCB.
On call for third stage of cooling, the supply air blower motor
& Compressor # 1 & 2 are operating but compressor # 3 is
not (the room thermostat fan switch is in the AUTO position).
1. Compressor # 3 will not energize simultaneously with
compressor 1 & 2, if a call for third stage of cooling is
received. The UCB delays compressor # 3 by 30
seconds to prevent a power surge, if after the delay
compressor # 3 doesn't energize on rd. stage call for
cooling, check for line voltage at the compressor
contactor 3, and that the contactor is pulled in. Check for
loose wiring between the contactor and the compressor.
2. If the compressor contactor 3 is pulled in and voltage is
supplied, lightly touch the compressor housing. If it is
hot, the compressor may be off on inherent protection.
Cancel any calls for cooling and wait for the internal
overload to reset. Test again when cool.
3. If the compressor contactor 3 is not pulled in, check for
24 volts at the compressor contactor coil. If 24 volt is
present and compressor contactor is not pulled in,
replace the contactor.
4. Failing the above, if voltage is supplied at the
compressor contactor 3, and it is pulled in, and the
compressor still doesn't operate, replace the
compressor.
5. If 24 volts is not present at compressor contactor 3,
check for 24 volts at the UCB terminal, C3. If 24 volts are
present, check for loose wiring between C3 and the
compressor contactor.
6. If 24 volts is not present at the C3 terminal, check for 24
volts from the room thermostat at the UCB Y3 terminal.
If 24 volts is not present from the room thermostat, check
for the following :
• 24 volts at the thermostat Y3 terminal.
• Proper wiring between the room thermostat and the
UCB.
• Loose wiring from the room thermostat to the UCB.
7. If 24 volts is present at the UCB Y3 terminal, the
compressor may be out due to an open high pressure
switch, low pressure switch or freezestat. Check for 24
volts at the HPS3, LPS3 and FS3 terminals of the UCB.
If a switch has opened, there should be a voltage
potential between the UCB terminals e.g., if LPS3 has
opened, there will be 24 volts of potential between the
LPS3 terminals.
8. If 24 Volts is present at the UCB Y3 terminal and none of
the protection switches have opened, the UCB may have
locked out the compressor for repeat trips. The UCB
should be flashing a code. If not, press and release the
ALARMS button on the UCB. The UCB will flash the last
five alarms on the LED. If the compressor is locked out,
remove any call for cooling at the thermostat or by
disconnection the thermostat wiring at the Y3 UCB
terminal. This will reset any installation, compressor lock
outs.
NOTE : While the above steps will reset any lockouts,
compressor # 1 & 2 will be held off for the ASCD, and the
compressor # 3 may be held off for a portion of the ASCD,
See the next step.
9. If 24 Volts is present at the UCB Y3 terminal and none of
the switches are open and the compressor is not locked
out, the UCB may have the compressor in an ASCD.
Check the LED for an indication of an ASCD cycle. The
ASCD should time out within 5 Min. press and release
the TEST button to reset all ASCDs.
10. The UCB Can be programmed to lock out compressor
operation during free cooling and in low ambient
conditions . These options are not enabled by default .
Local distributors can test the UCB for this programming.
11. If none of the above corrected the error, test the integrity
of the UCB, disconnect the C3 terminal wire and the
jumper it to the Y3 terminal, DO NOT jump the Y3 to C3
terminals. If the compressor engages, the UCB has
faulted.
12. If none of the above correct the error, replace the UCB.
On Call for fourth stage of cooling (50 TR models only) the
supply air blower motor & Compressor # 1, 2 & 3 are
operating but compressor # 4 is not ( the room thermostat fan
switch is in the AUTO position).
1. Compressor # 4 will not energize simultaneously with
compressor 1,2 & 3 if a call for fourth stage of cooling is
received. The UCB delays compressor # 4 by 30
seconds to prevent a power surge, if after the delay
compressor # 4 doesn't energize on 4th stage call for
cooling, check for line voltage at the compressor
contactor 4, and that the contactor is pulled in. Check for
loose wiring between the contactor and the compressor.
2. If the compressor contactor 4 is pulled in and voltage is
supplied, lightly touch the compressor housing. If it is
hot, the compressor may be off on inherent protection.