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© 2015 Watts Water Technologies
Phase 2 - Electrical Rough-in
To prevent the risk of personal injury and/or death, make sure power is not
applied to the product until it is fully installed and ready for final testing. All
work must be done with power turned off to the circuit being worked on.
STEP 2.1:
Circuit Breaker (Overcurrent Protection)
TapeMat(s) must be protected against overload by a circuit breaker. GFCI type (ground fault
circuit interrupter) or AFCI type (arc-fault circuit interrupter) breakers may be used if desired,
but are not necessary when using SunStat controls with integral GFCI
The rating of the breaker (see
Table 5)
is determined by the amp draw of the heating mats.
Add the amp ratings of all mats to be connected to the SunStat control (see Table 2 or the
Nameplate Label on the mat). If the total is less than 12 amps, use a 15 or 20 A breaker
(preference is 15 A). If the total is between 12 and 15 amps, use a 20 A breaker. If the total
is over 15 A, another circuit will be required with its own breaker and SunStat control.
Circuit Breakers and Supply Wire
Mat(s)
Supply Wire
Breaker
VAC
total amps
(AWG)*
qty type**
rating
120
up to 12 amps
14
1
SP
15 or 20 A
120 up to 15 amps
12
1
SP
20 A
240 up to 12 amps
14
1
DP
15 or 20 A
240 up to 15 amps
12
1
DP
20 A
* Recommended only. Follow local codes for wire gauge size.
** SP= single-pole, DP=double-pole
Table 5
STEP 2.2:
Install Electrical Boxes
SunStat Thermostat:
Install an extra-deep electrical box for the SunStat thermostat. Follow the instructions included
with the SunStat for complete information on location and wiring. The thermostat must be
located at least 4 feet (1.2 meters) away from shower openings to avoid being exposed to
water or touched by a person while in the shower area.
SunStat Relay:
Install an extra-deep electrical box for any SunStat Relay(s). The SunStat Relay is used when
more than 15 amps must be controlled by one SunStat Thermostat. Follow the instructions
included with the SunStat Relay for complete information on location and wiring.
Junction Boxes:
If a mat is to be located so its Power lead is not long enough to reach the SunStat Control or
SunStat Relay directly, a junction box must be installed. Do not attempt to make a connection
to other wiring without a junction box. Use a standard junction box with a cover, mounting
it below the subfloor, in the attic, in the wall, or in another location easily accessible after all
coverings are complete. If the SunStat sensor wire is not long enough to reach the SunStat
Control directly, it may be extended. A junction box may be required by local code to make this
connection. Follow the installation instructions included with the SunStat Control for details.
For construction with an existing wall or where the wall is covered, cut the necessary openings
to mount the electrical boxes listed above. Wait to install the boxes until all wiring is fed into
these locations to make it easier to pull the wire.
It may be possible to tap into
an existing circuit as long as
there is adequate capacity for
the mat(s) and any additional ap-
pliance, such as a hair dryer or
vacuum cleaner. Avoid circuits
which have lighting, motors,
exhaust fans, or hot tub pumps
due to possible interference.
