Installation of electrical wiring, Determine the size of the main power lines, Connect the main power – Greenheck Fan Make-Up Air Unit 470658 MSX User Manual

Page 8: Wire the optional convenience outlet, Wire the optional accessories, Wire the optional evaporative cooler

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8

®

Model MSX Make-Up Air

Installation of Electrical Wiring

IMPORTANT

Before connecting power to the unit, read and
understand the following instructions and wiring
diagrams. Complete wiring diagrams are attached
on the inside of the control center door(s).

IMPORTANT

All wiring should be done in accordance with the
latest edition of the National Electric Code ANSI/
NFPA 70 and any local codes that may apply. In
Canada, wiring should be done in accordance with
the Canadian Electrical Code.

IMPORTANT

The equipment must be properly grounded. Any
wiring running through the unit in the airstream must
be protected by metal conduit, metal clad cable or
raceways.

CAUTION

If replacement wire is required, it must have a
temperature rating of at least 105°C, except for an
energy cut-off or sensor lead wire which must be
rated to 150°C.

DANGER

High voltage electrical input is needed for this
equipment. This work should be performed by a
qualified electrician.

CAUTION

Any wiring deviations may result in personal injury
or property damage. Greenheck is not responsible
for any damage to, or failure of the unit caused by
incorrect final wiring.

IMPORTANT

Greenheck’s standard control voltage is 24 VAC.
Control wire resistance should not exceed
0.75 ohms (approximately 285 feet total length for
14 gauge wire; 455 feet total length for 12 gauge
wire). If the resistance exceeds 0.75 ohms, an
industrial-style plug-in relay should be wired in
place of the remote switch. The relay must be
rated for at least 5 amps and have a 24 VAC coil.
Failure to comply with these guidelines may cause
motor starters to chatter or not pull in, resulting in
contactor failures and/or motor failures.

1. Determine the Size of the Main Power
Lines

The unit’s nameplate states the voltage and the unit’s
MCA. The main power lines to the unit should be sized
accordingly. The nameplate is located on the outside
of the unit on the control panel side.

2. Provide the Opening(s) for the
Electrical Connections

Electrical openings vary by unit size and arrangement
and are field supplied.

3. Connect the Main Power

Connect the main power lines to the disconnect switch
and main grounding lug(s). Torque field connections to
20 in.-lbs.

4. Wire the Optional Convenience Outlet

The convenience outlet requires a separate 115 volt
power supply circuit. The circuit must include short
circuit protection which may need to be supplied by
others.

5. Wire the Optional Accessories

Reference the Ladder Diagram on the inside of the
control center door for correct wiring of the following
accessories:

• Blower Switch
• Heat Switch
• Indicating Lights
• Dirty Filter Indicator

• TSCP
• KSCP

NOTE

TSCP has number-to-number wiring.

NOTE

Large evaporative coolers may require a separate
power supply.

6. Wire the Optional Evaporative Cooler

Reference the Ladder Diagram on the inside of the
control center door for correct wiring of the pump and
the optional auto-drain and flush.

SUP HP

MCA

EXH HP

MOP

VOLTS

HZ

PH

Unit’s Total MCA

Voltage, Hertz, Phase

SUP HP

MCA

EXH HP

MOP

VOLTS

HZ

PH

Voltage, Hertz, Phase

Electrical Nameplate

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