Carrier 38AH044-084 - Manual (Page 40)

Table 16 — Index of Lead/Lag Circuits and Compressors
UNIT
38AH
044-084
STD
044-084
OPT
094 104 124 134
LEAD CIRCUIT A A A A
Module
124A
Module
134A
Compressor, Lead A1 A1 A1 A1 A1 A1
Compressor; Lag * A2 A2 A2 A2 A2
LAG CIRCUIT B † B B
Module
124B
Module
134B
Compressor, Lead B1 B1 B1 A1 A1
Compressor; Lag * * B2 A2 A2
LEGEND
OPT — Optional Single-Circuit Units
STD — Standard Dual-Circuit Units
*Circuit has only one compressor.
†Units have only one circuit.
Check Compressor Oil Level — After adjusting the
refrigerant charge, allow each circuit to run fully loaded for
20 minutes. Running oil level should be
1 ⁄
8
to 1 ⁄
3
up on the
sight glass. Stop the compressors at the field power supply
disconnect and check the crankcase oil level. Add oil only if
necessary to bring the oil into view in the sight glass. If oil
is added, run the circuit for an additional 10 minutes, then
stop and check oil level. If the level remains low, check the
piping system for proper design for oil return; also, check
the system for leaks.
If the initial check shows too much oil (too high in the
sight glass) remove oil to proper level. See Preliminary Oil
Charge for proper procedure for adding and removing oil.
When the above checks are complete, repeat the proce-
dure with the unit operating at minimum load conditions.
UNITS 38AH044-084,124, AND 134 — For this minimum
load check, run the lead compressor of each refrigeration cir-
cuit fully unloaded with the lag compressor not operating.
Unload the compressor(s) by turning the control set point
adjustment nut counterclockwise until the adjustment nut
stops. The unloader is now at 0 psig (0 kPag) set point. If
electrically actuated unloaders are installed, energize the so-
lenoid to unload the compressor. Recheck the compressor
oil level as described in Check Compressor Oil Level above.
Return unloader to original setting after checks are
complete.
UNITS 38AH094,104 — For this minimum load check, the
lead compressor (A1, B1) of each refrigeration circuit is un-
loaded. See Table 16. The lag compressor (A2, B2 [38AH104
only]) of each refrigeration circuit must not be operating.
Unload the compressor(s) by turning the control set point
adjustment nut counterclockwise until the adjustment nut stops.
The unloader is now at 0 psig (0 kPag) set point. If electri-
cally actuated unloaders are installed, energize the solenoid
to unload the compressor.
Return unloader to original setting after checks are
complete.
Final Checks — Ensure all safety controls are operat-
ing, control panel covers are on, and the service panels are
in place.
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