8 • Commercial Electric Water Heater Use and Care Guide
Electrical
GENERAL
The installation must conform with
these instructions and the local code
authority having jurisdiction and the
requirements of the power company.
In the absence of local codes, the
installation must comply with the
current editions of the Canadian
Electrical Code CSA C22.1.
An electrical ground is required to
reduce risk of electrical shock or
possible electrocution. The water
heater should be connected to a
separate grounded branch circuit with
over-current protection and disconnect
switch. The water heater should be
grounded in accordance with national
and local codes.
Voltage applied to the heater should
not vary more than +5% to -10% of
the model and rating plate marking for
satisfactory operation.
DO NOT ENERGIZE THE BRANCH
CIRCUIT FOR ANY REASON BEFORE THE
HEATER TANK IS FILLED WITH WATER.
DOING SO WILL CAUSE THE HEATING
ELEMENTS TO BURN OUT AND VOID
WARRANTY.
The factory wiring is attached to a
terminal block within the external
junction box unit. The branch circuit
is connected to the terminal block
within this junction box. The water
heater should be connected to a
separate, grounded, branch circuit with
overcurrent protection and disconnect
switch. The water heater should be
grounded in accordance with national
and local codes.
BRANCH CIRCUIT
The branch circuit wire size should
be established through reference to
the current edition of the Canadian
Electrical Code CSA C22.1 or other
locally approved source in conjunction
with the heater amperage rating.
The branch circuit should be sized at
125 percent of the heater rating and
further increase wire size as necessary
to compensate for voltage drop in long
runs.
CALCULATING AMPERAGE/
OVERCURRENT PROTECTION
The dual element heater is factory
wired for connection to a three wire,
three-phase delta branch circuit, non-
simultaneous operation. In addition, a
ground conductor is required.
Element connection is for non-
simultaneous operation. This means
only one element operates at a time.
The wiring diagram, on page 10, shows
the heater may be field converted to
simultaneous element operation by
moving the red wire on “J” terminal to
L1. It is then possible for both elements
to operate at once as determined by
the thermostats. Regardless of element
connection the heater operates in an
“unbalanced” fashion.
The heater may be field converted to
single-phase operation by moving the
wire on L3 of the terminal block to L2.
L3 is not used, see page 10.
The heater, now in single-phase
non-simultaneous operation, may
be field-converted to single phase
simultaneous operation by moving the
red wire on terminal “J” to L1, see page
10.
This is an example of calculating heater
amperage for both types of element
operation. From this, the branch circuit
conductor and overcurrent protection
sizing can be established.
Non-simultaneous:
(as factory wired)
Simultaneous:
(Field conversion)
3000 ÷ 240 =
12.5 amps*
3000 ÷ 240 =
12.5 amps*
12.5 x 1.73 = 21.6
amps
*NOTE: as a
single-phase
nonsimultaneous
unit.
*NOTE: as a
single-phase
simultaneous
unit the total is:
12.5 x 2 = 25 amps
The example is of a three-phase 240
volt unit with two, 6 kw elements. The
notations are for units field converted
to single-phase. Check the heater
model and rating plate for actual
specifications and substitute those
values in the following.
The rating of the overcurrent
protection should be computed on
the basis of 125 percent of the total
connected load amperage. Where the
standard ratings and settings do not
correspond with this computation, the
next higher standard rating or setting
should be selected.
GET
TING S
TAR
TED
GETTING STARTED
