Pentair MT125 - Electrical Connections

MASTERTEMP 125 Pool and Spa Heater Installation and User’s Guide 460906 Rev. D 8/2020
34
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: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.
IMPORTANT NOTICE: FOR HEATER BONDING, see page 36.
Please read the boxes headed “IMPORTANT!READMEFIRST!” on pages 50 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 Standards. A bonding lug is provided on the outside of the panel under the
vent for this purpose. See page 36 for BONDING instructions.
3. Electrical power circuits to the pool heater must follow all applicable codes and must be wired by a licensed electrician
to AS3000WiringRules.
4. All wiring between the heater and devices not attached to it, or between separate devices which are installed in the eld,
must be “Type T” wire rated for 35°C rise.
5. Thelter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.
6. Do not wire single-pole switches, including protective devices, into a grounded line. The heater is not sensitive to
polarity.
To control heaters that are operated in parallel, connect wiring at same locations on heater as 2-Wire or 3-Wire Control.
It is imperative that each control circuit is isolated from the other control circuits, to avoid that current will ow from
Figure 30.
AC Plug
120 Volt
or
240 Volt
ELECTRICAL CONNECTIONS
Electrical Rating: 50 Hz 240 Volts AC, single phase: Enclose the incoming AC power line to the heater in
an approved exible conduit connected directly to the junction box on the inside of the access door panel. Line voltage
eld wiring should be 14 gauge, with a circuit capacity of 15 Amps. Note: Note: The heater operating AMP draw is
about 5 AMPS at 120 VAC and 2.5 AMPS at 240 VAC. A 15 AMP circuit capacity is required for the inrush
current at startup. The heater is supplied with a 250 VAC, 10 AMP, 50 Hz power cord (AS/NZS 3112) approved for
outdoor use. The powercord wire is 3 x 16 AWG (3 x 10 mm2).
Figure 29.
Section 1. Installation Instructions