IOMM AGZ-5
AGZ 026B through 130B
93
7. Leak detector is applied externally to refrigerant joints at the factory. Do not
confuse this residue with an oil leak.
8. Connect refrigerant service gauges to each refrigerant circuit before starting unit.
Electrical Check Out
CAUTION
Electrical power must be applied to the compressor crankcase heaters 24 hours before
starting unit to drive off refrigerant from the oil.
1. Open all electrical disconnects and check all power wiring connections. Start at
the power block and check all connections through all components to and including
the compressor terminals. These should be checked again after 3 months of
operation and at least yearly thereafter.
2. Check all control wiring by pulling on the wire at the spade connections and
tighten all screw connections. Check plug-in relays for proper seating and to
insure retaining clips are installed.
3. Put System Switch (S1) to the Emergency Stop position.
4. Put both circuit #1 & #2 switches to the Pumpdown and Stop position.
5. Apply power to the unit. The panel Alarm Light will stay on until S1 is closed.
Ignore the Alarm Light for the check out period. If you have the optional Alarm
Bell, you may wish to disconnect it.
6. Check at the power block or disconnect for the proper voltage and proper voltage
between phases. Check power for proper phasing using a phase sequence meter
before starting unit.
7. Check for 120Vac at the optional control transformer and at TB-2 terminal #1 and
the neutral block (NB).
8. Check between TB-2 terminal #7 and NB for 120Vac supply for transformer #2.
9. Check between TB-2 terminal #2 and NB for 120Vac control voltage. This
supplies the compressor crank case heaters.
10. Check between TB-3 terminal #17 and #27 for 24Vac control voltage.
Operation
Hot Gas Bypass (Optional)
This option allows the system to operate at lower loads without the ON-OFF cycling of
the compressor. When the hot gas bypass option is used, it is required to be on both
refrigerant circuits because of the lead / lag feature of the controller.
This option allows passage of discharge gas into the evaporator inlet (between the TX
valve and the evaporator) which generates a false load to supplement the actual chilled
water load.
Note:
The hot gas bypass valve cannot be used to generate a 100% false load.
The valve that is supplied can provide a load of approximately 10 tons. The system
load added to the ten tons of the hot gas bypass valve has to exceed the compressor
capacity for stage 1 compressors for stable system operation. This requires 3-6 tons of
system load.
Summary of Contents for AGZ026BS
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