Carrier P4, P5030-100, P3, 48P2 installation instructions Route Field Wiring

Step 11 — Route Field Wiring

UNIT SIZES 030-060 — Field wiring can be brought into the unit through the basepan and roof curb or through the corner post in the side of the unit next to the control box.

A 31/2-in. FPT coupling for field power and a 3/4-in. FPT coupling for 24 v control wiring are provided in the basepan. There are two 7/8-in. pilot holes in the corner post as shown on the certified drawings. Use these holes as pilot holes for mak- ing the hole for field-supplied conduit in the corner post for field power wiring.

CAUTION

Use care when drilling near condenser coil. Damage to unit could result.

If field power wiring is brought through the roof curb, route wiring out through one of the holes to the field-supplied dis- connect and then back into the unit through the other hole. See Fig. 38 and 39 for recommended disconnect location.

If power wiring is brought through the side of the unit, route wiring from field-supplied disconnect through top hole into unit.

If control wiring is to be brought in through the side of the unit, a 7/8-in. diameter hole must be drilled in the corner post next to the control box.

UNIT SIZES 070-100 — Field wiring is brought into the unit through the bottom of the control box. Wiring can be brought through the roof curb through field-supplied watertight connec- tions. See Fig. 40.

A 45/32-in. hole for field power wiring and a 7/8-in. hole for

24 v control wiring are provided in the bottom of the control box. Field-supplied couplings must be used when routing wir- ing into the control box.

See Fig. 40 for recommended disconnect location.

Step 12 — Make Field Electrical Connections

IMPORTANT: Units with VFDs (variable frequency drives) generate, use, and can radiate radio frequency energy. If units are not installed and used in accordance with these instructions, they may cause radio interfer- ence. They have been tested and found to comply with limits of a Class A computing device as defined by FCC (Federal Communications Commission) regulations, Subpart J of Part 15, which are designed to provide rea- sonable protection against such interference when oper- ated in a commercial environment.

POWER WIRING — Units are factory wired for the voltage shown on the unit nameplate. The main terminal block is suit- able for use with aluminum or copper wires. Maximum wire size varies according to disconnect size.

Units without Factory-Installed Disconnect — When install- ing units, provide a disconnect per NEC (National Electrical Code) of adequate size (MOCP [maximum overcurrent protec- tion] of unit is on the informative plate). All field wiring must comply with NEC and all local codes. Size wire based on MCA (minimum circuit amps) on the unit informative plate. See Fig. 41 for power wiring connections to the unit power

terminal block and equipment ground. Maximum wire size is two (2) 500 MCM (maximum wire size) conductors per pole.

Units with Factory-Installed Disconnect — The factory- installed disconnect is an interlocking, door-type. The discon- nect handle locks the door when it is in the ON position. The disconnect handle must be in the OFF position to open the con- trol box door. The disconnect is located in the control box be- hind the control box door for all units. See Fig. 42.

All field wiring must comply with NEC and all local codes. Wire must be sized based on MCA (minimum circuit amps) on the unit informative plate. See Fig. 43 for power wiring con- nections to the unit disconnect and equipment ground.

DISCONNECT SIZE	QUANTITY...MAXIMUM WIRE SIZE
	(MCM)
250 Amps	1...300
400 Amps	1...600
600 Amps	2...600

Operating Voltage — Operating voltage to the compressor must be within the voltage range indicated on the unit name- plate. Voltages between phases must be balanced within 2%, and the current must be balanced within 10%. See Tables 10-25 for unit electrical data.

Use the following formula to determine the percentage of voltage imbalance.

Voltage Imbalance

=100 x max voltage deviation from average voltage average voltage

Example: Supply voltage is 460-3-60.

AB = 452 v

BC = 464 v

AC = 455 v

Average Voltage =	455 + 464 + 455
	3
=	1371
	3
=	457

Determine maximum deviation from average voltage:

(AB) 457 – 452 = 5 v (BC) 464 – 457 = 7 v (AC) 457 – 455 = 2 v Maximum deviation is 7 v.

Determine percent voltage imbalance:

% Voltage Imbalance = 100 x	7
	457

= 1.53%

This amount of phase imbalance is satisfactory as it is be- low the maximum allowable 2%.

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

Unit failure as a result of operation on improper line voltage or excessive phase imbalance constitutes abuse and may cause damage to electrical components.

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