P/N 475114 Rev. F 8/2020
MASTERTEMP 125 Pool and Spa Heater Installation and User’s Guide
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ELECTRICAL CONNECTIONS
Electrical Rating: 50 Hz 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.
Note: The heater operating AMP draw is
about 2.5 AMPS at 240 VAC. A 15 AMP circuit capacity is required for the inrush current at startup.
CAUTION
This heater is designed to operate at 240 VAC. It is not recommended to be connected to OR operate on a 208 VAC.
NOTE: Before making any electrical connections to the power supply, remove the access door panels, open the control
box and check the correct plug (240 volt) is installed.
NOTE: If any of the original wiring supplied with this heater must be replaced, installer must supply (1.16 mm, 600V, 105°
C. IEC approved low energy stranded) copper wire or it’s equivalent.
CAUTION
The heater ships from the Factory with the 240V 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 volts line current, the heater will not operate.
Please read the boxes headed
“IMPORTANT! READ ME FIRST!”
on page 23 and 27 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 current European Standard Codes of Practice. A bonding lug is provided on the outside of
the panel under the vent for this purpose. See page 19 for BONDING instructions.
3. Electrical power circuits to the pool heater must follow European Standard codes of Practice.
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 15 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.
Figure 23.
AC Plug
240 Volt
(Red wires,
Top plug)
Section 1. Installation
