Benchmark Electrical Power Guide GF-2060

Technical Bulletin

1 Revised 4/20/07

GENERAL

Benchmark (BMK) Gas Fired Boilers are fully factory wired packaged units which require simple power wiring as part of the installation. This technical guide is intended to help designers provide electrical power wiring (Line Voltage) to BMK units. Control wiring details are in other applications depending upon application. This is intended as a guide only, and cannot include all alternatives, situations, or be totally inclusive. To comply with all codes and authorities having jurisdiction, designers and installers must plan the electrical wiring carefully and execute the installation completely. Emergency shutoffs, fusible fire switches, break glass stations, and other electrical requirements should be considered and installed whenever necessary.

Boiler Electrical Requirements The Benchmark boiler is ordered to one of the following electrical supply conditions.

1. 220/1/60 @ 20 amps 2. 208-230/3/60 @ 15 amps 3. 460/3/60 @ 15 amps

The distribution block for field connection is located in the upper right of the control box. All copper wire must be connected to the terminal distribution block. 200 V for 220/1/60, 190 V for 208-230/3/60 and 415 V for 460/3/60 are the minimum allowable supply voltages to the design. Lower voltages will result in increased wear and premature failure of the blower motor. Wire size and type should be made per the National Electrical Code based on length and load.

Control Panel

Service Disconnect Switch

Knock-Out for alternate electricalconduit to Service Switch

Diagram 1

Service Switch Typical Location

2

TERMINAL BLOCK

Diagram 2 Distribution Block Location

Provisions for Service Designers must provide emergency shutoffs and other devices to satisfy electrical codes. It is also recommended to provide an electrical shutoff disconnect switch of suitable load carrying characteristics on or near each BMK boiler. No electrical boxes or field components should be mounted to the surface of the boiler or where they would interfere with the removal of the side or top panels for maintenance. The disconnect switch should be mounted near the unit as illustrated in Diagram 1. Wiring conduit, EMT, or other wiring paths should not be secured to the unit, but supported externally. Electricians should be instructed as to where the wiring conduit should be located, such as away from the relief valve discharge, drains, etc. All electrical conduit and hardware should be installed so that it does not interfere with the removal of any cover, inhibit service or maintenance, or prevent access between the unit and walls or another unit. Single Phase Boiler Wiring When a single phase BMK unit is to be installed, a dedicated protected circuit should be provided from the power source to the boiler. No other electrical devices should be permanently wired on the same circuit. An emergency switch (electrical shutoff) must be in series with the power to the unit. Refer to Diagram 3.

L1

L2

NEU

GND

Distribution Blockin Control Box

Inside Boiler Control Panel

Disconnect Switch2 Pole 20 AMP

L1

L2

NEU

GND

2 POLE 20 AMPCIRCUIT BREAKER

220 LABELL1L2 220 V/1/60 Hz, 20 AMP

L1 120V/1/60 Hz, 20 AMPNEU

Diagram 3 220v/1/60 Wiring Schematic

3

Three Phase Boiler Wiring When a three phase BMK unit is to be installed, a dedicated protected circuit should be provided from the power source to the boiler. No other electrical devices should be permanently wired on the same circuit. An emergency switch (electrical shutoff) must be in series with the power to the unit. Refer to Diagram 4 for 208-230V wiring and Diagram 5 for 460V wiring.

Multiple Unit Wiring Whenever multiple units are installed within the same mechanical spaces, electrical code requirements call for a single electrical shutoff for emergency use. It is the responsibility of the electrical designer to comply with local codes and regulations affecting an individual installation.

L2

L1

L3

NEU

GND

Distribution Blockin Control Box

Inside Boiler Control Panel

Disconnect Switch3 Pole 15 AMP

L1

L2

L3

NEU

GND

5 Wire208 -230V/3/60Hz

3 POLE 15 AMPCIRCUIT BREAKER

208-230 LABELL1L2 208 V/3/60 Hz, 15 AMPL3

L1 120V/1/60 Hz, 15 AMPNEU

Diagram 4 208-230/3/60 Wiring Schematic- 5 Wire

L2

L1

L3

GND

Distribution Blockin Control Box

Inside Boiler Control Panel

Disconnect Switch3 Pole 15 AMP

L1

L2

L3

GND

4 Wire460V/3/60Hz

3 POLE 15 AMPCIRCUIT BREAKER

460 LABELL1L2 460V/3/60 Hz, 15 AMPL3

L1 120V/1/60 Hz, 15 AMPNEU

Diagram 5 460/3/60 Wiring Schematic- 4 Wire

4

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HOT WATER SYSTEMS AERCO INTERNATIONAL, INC. 159 PARIS AVE. NORTHVALE

N.J. 07647 201-768-2400 TELEX 135450 FAX 201-768-7789

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