Carrier WeatherMaker 48TC Series - Pressures (Cooling Mode); Refrigerant Suction and Discharge; General Checks; Humidi-MiZer Start-Up Steps

Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Catalog No. 04-53480288-01 Printed in U.S.A. Form 48TC-17-30-02SM Pg CL-2 10-2020 Replaces: 48TC-17-30-02SM
© 2020 Carrier
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CUT ALONG DOTTED LINE CUT ALONG DOTTED LINE
PRESSURES (COOLING MODE)
REFRIGERANT SUCTION CIRCUIT 1 _____________ PSIG _____________ °F
CIRCUIT 2 _____________ PSIG _____________ °F
REFRIGERANT DISCHARGE CIRCUIT 1 _____________ PSIG _____________ °F
CIRCUIT 2 _____________ PSIG _____________ °F
Verify that 3-phase fan motor and blower are rotating in correct direction (Y/N) _____
Verify that 3-phase scroll compress
or is rotating in the correct direction (Y/
N) _____
VERIFY REFRIGERANT CHARGE USING CHARGING CHARTS (Y/N) _____
GENERAL
Economizer minimum vent and changeover settings to job requirements (if equipped) (Y/N) _____
Verify smoke detector unit shutdown by utilizing magnet test (Y/N) _____
III. HUMIDI-MIZER
®
START-UP
STEPS
1. Check CTB for jumper 5, 6, 7 (Jumper 5, 6, 7 must be cut and open) (Y/N) _____
2. Open humidistat contacts (Y/N) _____
3. Start unit In cooling (Close Y1) (Y/N) _____
OBSERVE AND RECORD
A. Suction pressure _______________ PSIG
B. Discharge pressure _______________ PSIG
C. Entering air temperature _______________ °F
D. Liquid line temperature at outlet or reheat coil _______________ °F
E. Confirm correct rotation for compressor (Y/N) _____
F. Check for correct ramp-up of outdoor fan motor as condenser coil warms (Y/N) _____
4. Check unit charge per charging chart (Y/N) _____
(Jumper 32L Motormaster
®
temperature sensor during this check. Remove jumper when complete.)
5. Switch unit to high-latent mode (sub-cooler) by closing humidistat with Y1 closed (Y/N) _____
OBSERVE
A. Reduction in suction pressure (5 to 7 psi expected) (Y/N) _____
B. Discharge pressure unchanged (Y/N) _____
C. Liquid temperature drops to 50°F to 55°F range (Y/N) _____
D. LSV solenoid energized (valve closes) (Y/N) _____
6. Switch unit to dehumid (reheat) by opening Y1 (Y/N) _____
OBSERVE
A. Suction pressure increases to normal cooling level
B. Discharge pressure decreases (35 to 50 psi) (Limited by Motormaster)
C. Liquid temperature returns to normal cooling level
D. LSV solenoid energized (valve closes)
E. DSV solenoid energized, valve opens
7. With unit in dehumid mode close W1 compressor and outdoor fan stop; LSV and DSV solenoids de-energized
(Y/N) _____
8. Open W1 restore unit to dehumid mode (Y/N) _____
9. Open humidistat input compressor and outdoor fan stop; LSV and DSV solenoids de-energized (Y/N) _____
10. Restore set-points for thermostat and humidistat (Y/N) _____
REPEAT PROCESS FOR 2 COMPRESSOR SYSTEMS