HTP Mod Con 300 HL, Installation & Maintenance Manual

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PART 7 – FIELD WIRING
ELECTRICAL SHOCK HAZARD - For your safety, turn off electrical power supply at service entrance
panel before making any electrical connections. Failure to do so can result in severe personal injury or
death.
Wiring must be N.E.C. Class 1.
If original wiring supplied with the boiler must be replaced, use only TEW 105
o
C wire or equivalent.
Boiler must be electrically grounded as required by National Electrical Code ANSI/NFPA 70 – Latest
Edition.
A. INSTALLATION MUST COMPLY WITH:
1. National Electrical Code and any other national, state, provincial or local codes or regulations.
2. In Canada, CSA C22.1 Canadian Electrical Code Part 1, and any local codes.
B. FIELD WIRING
All connections made to the boiler in the field are done inside the electrical junction box located on the
side of the unit. The electrical junction box is located on the right side of the Mod Con 300, and the left
side of both the Mod Con 500 and 850. Multiple knockout locations are available to route field wires into
and out of the electrical junction box.
The control used in the Mod Con series of boilers is capable of directly controlling 2 pumps when in
standard mode and 3 pumps when configured as a cascade master boiler. When configured as a
standard unit, each pump output can provide a maximum of 3 amps at 120 volts. If pumps used require
more than this amount of power, an external contactor or motor starter is needed. If the boiler is
configured as a cascade master, the system pump output is a dry contact output capable of switching 5
amps at 120 volts in addition to the boiler pump and DHW pump outputs sourcing 3 amps each.
The electrical junction box has separate, clearly marked terminal strips for line voltage and low voltage
wiring. Special jacks are provided for trouble-free cascade system wiring using standard CAT3 or CAT5
patch cables.
C. LINE VOLTAGE WIRING
1. Connect the incoming power wiring to the line voltage terminal strip in the electrical junction box at
terminals LINE 120V, Neutral, and Ground (shown in Figure 24).
2. A line voltage fused disconnect switch may be required to be externally mounted and connected
according to local wiring codes.
3. Connect the central heating pump to the terminals marked BOILER HOT, BOILER NEUT, and BOILER
GRD. The connections shown are suitable for a maximum continuous pump draw of 3 amps at 120 volts.
If the pump requires more current or voltage other than the 120 volts supplied, an external motor starter
or contactor will be required.