Trane CVGF1000, Инструкция по установке, эксплуатации и обслуживанию

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3. The Large display ™ display module 1A22, receives 24 Vdc power from the IPC
bus.
AdaptiView and Wye-Delta Starter Control Circuits (Sequence of Oper-
ation)
Logic Circuits within the various modules will determine the starting, running, and
stopping operation of the chiller. When operation of the chiller is required the chiller
mode is set at ‘‘Auto.” Using customer-supplied power, the chilled water pump relay
(5K1) is energized by the 1A5 Module output at 1A5¬J2-4, and chilled water flow must
be verified within 4 minutes 15 seconds by the 1A6 module. The main processors logic
decides to start the chiller based on the differential to start setpoint. With the differen-
tial to start criteria met module 1A5 then energizes the condenser water pump relay
(5K2) using customer-supplied power at 1A5 J2-1.
Based on the restart inhibit function and the differential to start setpoint, oil pump (4M3)
will be energized by 1A9 module (1A9-J2-7). The oil pressure switch must be closed for
30 continuous seconds and condenser water flow verified within 4 minutes 15 seconds
for the compressor start sequence to be initiated.
When less than 5 seconds remain before compressor start, a starter test is conducted
to verify contactor state prior to starting the compressor. The following test or start se-
quence is conducted for “Wye-Delta” starters:
1. Test for transition complete contact open (1A23X or 2A1-J12-2) –160 to 240 msec.
An MMR diagnostic will be generated if the contact is closed.
2. Delay time - 20 msec.
3. Close start contactor (2K1) and check for no current - 500 msec. If currents are de-
tected, the MMR diagnostic ‘‘Starter Fault Type I’’ is generated and closes for one
second.
4. Delay time - 200 msec. (Opens 2K1).
5. Close shorting contactor, (2K3) and check for no current (1A23 or 2A1 J4-1) for one
second. If currents are detected the MMR diagnostic ‘‘Starter Fault Type II’’ is gen-
erated. (Starter Integrity test)
6. If no diagnostics are generated in the above tests, the stop relay (2A1- J10) is
closed for two seconds and the start relay (2A1-J8) is closed to energize the start
contactor (2K1).
The shorting contactor (2K3) has al-
ready been energized from (F) above. The compressor motor (4M1) starts in the
“Wye” configuration, an auxiliary contact (2K1-AUX) locks in the start contactor
(2K1) coil.
7. After the compressor motor has accelerated and the maximum phase current has
dropped below 85 percent of the chiller nameplate RLA for 1.5 seconds, the starter
transition to the “Delta” configuration is initiated.
8. The transition contactor (2K4) is closed through relay 2A1-J2, placing the transi-
tion resistors (2R1, 2R2, and 2R3) in parallel with the compressor motor windings.
9. The shorting contactor (2K3) is opened through the opening of relay 2A1-J4 100
msec after the closure of the transition relay 2A1-J2.
10. The run contactor (2K2) is closed through relay 2A1-J6, shorting out the transition
resistors 260 milliseconds after the opening of the shorting relay 2A1-J4. This plac-
es the compressor motor in the “Delta” configuration and the starter module waits
to look for this transition for 2.35 seconds through the closure of the transition
complete contacts 2K2- AUX at module 2A1-J12 input.
CVGF-SVX03B-EN
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Control System Components