Carrier 30HK040-060, 30HW018-040, 30HL050 specifications

Step 6 Ð Make Electrical Connections Ð All field wiring must comply with local code requirements. Electrical data for the complete unit and for the compressors is shown in Tables 4A and 4B. See Fig. 17 and 18 for ®eld wiring connections. A ®eld-supplied branch circuit disconnect switch that can be locked in either OPEN or OFF position must be installed.

30HK, HL UNITS Ð On all 60 Hz units, a fused (15 amp maximum), 115 v control circuit must be supplied by either a separate power source or by using a minimum 300 va trans- former. On 208/230 and 460 v units, control circuit power can be supplied by accessory transformer part no. 07EA900051. Check to be sure that installation of the 115 v control power source meets all local codes.

On all 50 Hz units, a fused (15 amp maximum), 230 v control circuit must be ®eld supplied. On 200-3-50 units, power for the control circuit can be supplied by connecting a ®eld- supplied fuse (15 amp maximum) between TB1 and TB2 for L1 overcurrent protection. On 400-3-50 units, power for the control circuit can be supplied by connecting a ®eld- supplied fuse (15 amp maximum) between TB1 and a neu- tral leg from TB2 for L1 overcurrent protection. On all units, check to be sure that installation of the 230 v control power source meets all local codes.

30HW UNITS Ð Control circuit power is 24 v and 115 v on all units, and is supplied by factory-installed control

Control Box, Controls Section Ð The control box controls section contains the following components:

·temperature controller

·control relay(s)

·control module(s)

·low-voltage control transformer(s)

·terminal block for ground current sensing accessory

Control Box, Field Control Wiring Section Ð Inside this section is a 10-terminal (30HK, HL) or 14-terminal (30HW), low-voltage, ®eld-wiring terminal strip. All low-voltage ®eld- wiring connections are made to this terminal block. Seven 3¤4-in. (19 mm) knockouts are provided for ®eld wiring in this section. Connections for chilled ¯uid ¯ow switch, chilled ¯uid pump interlock, condenser pump interlock, remote alarm output, and ground current sensor accessory are made at this location. The remote condenser relay connections are made to a separate 4-terminal (30HK, HL) or 3-terminal (30HW) ®eld wiring strip. See Fig. 17-20 for speci®c location of connections.

Unbalanced 3-Phase Supply Voltage Ð Never operate a com- pressor where a phase imbalance in the supply voltage is greater than 2%. Use the following formula to determine the percent voltage imbalance:

% Voltage Imbalance =

transformers.

ALL UNITS Ð Inside the control box are terminals for ®eld

100 x

max voltage deviation from average voltage

average voltage

power and ground (earth) wiring, as well as a terminal for a neutral wire when needed (380-3-60 and 400-3-50 units only). A ground wire must be installed with each ®eld power sup- ply. Compressor are wired standard from the factory for across- the-line start. As a factory-installed option, all 025-060 sizes are available wired for part-wind start (special order option on 30HK, HL unit).

Example: Supply voltage is 240-3-60

AB = 243 v

BC = 236 v

AC = 238 v

Refer to Tables 4A and 4B for electrical data.

Flow Switch Ð A cooler ¯ow switch is required for all units, and must be ®eld-installed. The Carrier ¯ow switch acces-

Average Voltage =

243 + 236 + 238

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sory (part number 30HW900003), is available for this pur- pose. Flow switch wiring terminals are located in the ®eld wiring compartment of the control box. The ¯ow switch should be wired between terminals TB3-1 and TB3-7 for 30HK, HL units or between terminals TB2-7 and TB2-13 for 30HW units. The factory jumper wire between these 2 terminals must be removed for proper operation of the ¯ow switch.

Control Box, Power Section Ð The electrical power supply is brought in through the top left-hand side (30HK, HL) or

= 239 v

Determine maximum deviation from average voltage:

(AB) 243 - 239 = 4 v (BC) 239 - 236 = 3 v (AC) 239 - 238 = 1 v

Maximum deviation is 4 v.

Determine percent voltage imbalance:

right-hand side (30HW) of the control box (see Fig. 19 and

% Voltage Imbalance = 100 x

4

20). The knockout accepts up to a 3-in. (76 mm) conduit for 30HK, HL units, and a 13¤4- to 21¤2-in. (44 to 64 mm) conduit for 30HW units. Pressure-lug connections on the terminal blocks are suitable for copper, copper-clad aluminum, or alu- minum conductors.

The control box power section contains the following components:

·power terminal block

·compressor circuit breaker(s)

·compressor contactor(s)

·high-voltage transformer (30HW units only)

·control-circuit circuit breaker for 24-v circuit

·unit ON-OFF switch

·unit service light

·ground lug

·neutral terminal (380-3-60 and 400-3-50 units)

·terminal block for ground current sensing accessory

239

= 1.7%

This amount of phase imbalance is satisfactory as it is below the maximum allowable 2%.

IMPORTANT: If the supply voltage phase imbalance is more than 2%, contact your local utility company immediately.

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