Section 3. Installation Instructions
ELECTRICAL CONNECTIONS
Electrical Rating: 60 Hz 120 / 240 Volts AC, single phase
Enclose the incoming AC power line to the heater, in an approved flexible conduit connected directly to the junction box on
the inside of the access door panel. Line voltage field wiring should be 14 gauge, with a circuit capacity of 15 Amps.
This heater is designed to operate at 120 or 240 VAC. It is not recommended to be connected to OR operate on a 208 VAC.
• Before making any electrical connections to the power supply, remove the access door panels, open the control box and plug in the
correct plug (120 VAC or 240 VAC). See plugs below.
The heater ships from the Factory with the 240 VAC plug installed. Installing the 120V plug and then connecting the
heater to 240V line current will immediately destroy the transformer, control board and ignition control module, and
will void warranty. If you install the 240V plug and connect the heater to 120 VAC line current, the heater will not
operate.
• If any of the original wiring supplied with this heater must be replaced, installer must supply (No. 18 AWG, 600V, 105° C. U.L.
approved AWM low energy stranded) copper wire or it's equivalent.
Please read the boxes headed "IMPORTANT! READ ME FIRST!" on pages 38 and 42 before proceeding.
1. All wiring must be in accordance with all applicable codes.
2. The heater, when installed, must be electrically grounded and bonded in accordance with local codes or, in the absence
of local codes, with the National Electrical Code or the Canadian Electrical Code (as applicable). A bonding lug is
provided on the outside of the panel under the vent for this purpose.
3. Electrical power circuits to the pool heater must follow local codes and National Electrical Code or Canadian Electrical
Code (as applicable).
4. All wiring between the heater and devices not attached to it, or between separate devices which are installed in the
field, must be "Type T" wire rated for 35°C rise.
5. All line voltage wiring shall be enclosed in approved flexible conduit, and shall be securely attached to the field wiring
box located inside the access door panel. The conduit or cable connector at the field wiring box should contain an
insulating bushing or its equivalent to prevent abrasion of the wires as they enter the box.
6. The filter pump should run continuously when the heater is on, and for at least 5 minutes after the heater
turns off. Any switches in the pump circuit (including circuit breakers)
that can disconnect the pump must also disconnect the heater.
7. Do not wire single-pole switches, including protective devices, into a
grounded line. The heater is not sensitive to polarity.
Connect the L1 of the power supply to the black wire, the L2 or neutral
lead to the red wire, and the ground wire to the green wire. A time clock
controlling the filter pump should have a low-voltage Fireman's Switch
that switches off the heater at least 15 minutes before shutting off the
pump.
Always use crimp type connectors when
connecting two wires.
AC VOLTAGE SELECT PLUGS:
(120 VAC or 240 VAC)
Rev. N 10/2018
CAUTION
NOTE
CAUTION
AC Plug
120 Volt
or
240 Volt
Figure 20.
MASTERTEMP Pool and Spa Heater Installation and User's Guide
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