Compressor Mounting; Internal Wiring; Refrigerant Service Ports; Compressor Rotation - Carrier WeatherMaker 50TC 17-30 Series Service And Maintenance Instructions

Single package rooftop unit with electric cooling and optional electric heat with puron (r-410a) refrigerant
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Compressor Mounting

Compressors are internally spring mounted. Do not loosen or re-
move compressor hold down bolts.

Internal Wiring

Check all electrical connections in unit control boxes. Tighten as
required.

Refrigerant Service Ports

Each unit system has two
1
service ports: one on the suction line, and one on the compressor
discharge line. Be sure that caps on the ports are tight.

Compressor Rotation

CAUTION
EQUIPMENT DAMAGE HAZARD
Failure to follow this caution can result in premature wear and
damage to equipment.
Scroll compressors can only compress refrigerant if
rotating in the right direction. Reverse rotation for
extended times can result in internal damage to the
compressor. Scroll compressors are sealed units and
cannot be repaired on site location.
NOTE: When the compressor is rotating in the wrong direction,
the unit will make an elevated level of noise and will not provide

cooling.

On 3-phase units with scroll compressors, it is important to be cer-
tain compressor is rotating in the proper direction. To determine
whether or not compressor is rotating in the proper direction:
1. Connect service gages to suction and discharge pressure
fittings.
2.
Energize the compressor.
3.
The suction pressure should drop and the discharge pressure
should rise, as is normal on any start-up.
If the suction pressure does not drop and the discharge pressure
does not rise to normal levels:
1.
Note that the evaporator fan is probably also rotating in the
wrong direction.
2.
Turn off power to the unit and install lockout tag.
3.
Reverse any two of the unit power leads.
4.
Reapply electrical power to the compressor.
5.
The suction pressure should drop, and the discharge pressure
should rise, which is normal for scroll compressors on start-
up.
6.
Replace the compressor if suction/discharge pressures are not
within specifications for the specific compressor.
Cooling
Set space thermostat to OFF position. To start unit, turn on main
power supply. Set system selector switch at COOL position and
fan switch at AUTO position. Adjust thermostat to a setting below
room temperature. Compressor starts on closure of contactor.
Check unit charge. Refer to Refrigerant Charge section.
Reset thermostat at a position above room temperature. Com-
pressor will shut off. Evaporator fan will shut off after a
30 second delay.
/
-in. SAE flare (with check valves)
4
To shut off unit, set system selector switch at OFF position. Reset-
ting thermostat at a position above room temperature shuts unit off
temporarily until space temperature exceeds thermostat setting.
NOTE: The default value for the evaporator-fan motor on/off de-
lay is 45 seconds. Based upon unit operating conditions, the on de-
lay can be reduced to 0 seconds and the off delay can be extended
to 180 seconds. When one flash of the LED is observed, the evap-
orator-fan on/off delay has been modified.

Ventilation (Continuous Fan)

Set fan and system selector switches at ON and OFF positions, re-
spectively. Evaporator fan operates continuously to provide con-
stant air circulation. When the evaporator-fan selector switch is
turned to the OFF position, there is a 30 second delay before the
fan turns off.

START-UP, PREMIERLINK CONTROLS

NOTICE: SET-UP INSTRUCTIONS
All set-up and set point configurations are factory set and field-
adjustable.
Refer to the PremierLink Installation, Start-Up and Configura-
tion Instructions for specific operating instructions for the con-
troller. Have a copy of this manual available at unit start-up.

START-UP, RTU-OPEN CONTROLS

NOTICE: SET-UP INSTRUCTIONS
Refer to the following manuals for additional installation, wir-
ing and troubleshooting information for the RTU-OPEN Con-
troller.: "Controls, Start-up, Operation and Troubleshooting In-
structions," "RTU Open Installation and Start-up Guide" and
"RTU-Open Integration Guide". Have a copy of these manuals
available at unit start-up.

FASTENER TORQUE VALUES

Table 27 — Torque Values
LOCATION
Supply fan motor
mounting
Supply fan motor
adjustment plate
Motor pulley setscrew
Fan pulley setscrew
Blower wheel hub
setscrew
Bearing locking collar
setscrew
Compressor mounting
bolts
Condenser fan motor
mounting bolts
Condenser fan hub
setscrew
57
TORQUE VALUES
120 in.-lb (13.6 Nm) ± 12 in.-lb (1.4Nm)
120 in.-lb (13.6 Nm) ± 12 in.-lb (1.4Nm)
72 in.-lb (8.1 Nm) ± 5 in.-lb (0.6 Nm)
72 in.-lb (8.1 Nm) ± 5 in.-lb (0.6 Nm)
72 in.-lb (8.1 Nm) ± 5 in-.lbs (0.6 Nm)
50 in.-lb (6.2 Nm) -60 in.-lb (6.8 Nm)
65 in.-lb (7.3 Nm) -75 in.-lb (8.5Nm)
20 in.-lb (2.3 Nm) ± 2 in.-lb 0.2 Nm)
84 in.-lb (9.5 Nm) ± 12 in.-lb (1.4 Nm)

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