•
Safety wiring must be NEC Class 1.
•
Heater must be electrically grounded as required
by the NEC.
•
In Canada, CSA C22. 1 C.E.C. Part 1.
XTherm heaters are wired for 120VAC single phase
power. Models 1005 and 1505, except WH 1505 mod-
els equipped with a heater pump for hard water,
require 15A service for the heater and 15A service for
the heater pump or a single 30A rated circuit. Model
1505 heaters equipped for hard water require 15A
service for the heater and 20A service for the heater
pump or a single 40A rated circuit. Model 2005
heaters require 20A service for the heater and 20A
service for the heater pump, or a single 40A service.
Consult the wiring diagram shipped with the heater.
Use appropriately sized wire as defined by NEC, CSA
and/or local codes. All primary wiring should be rated
for 125% of the minimum required service. Before
starting the heater, verify that the correct 120VAC volt-
age is being supplied to the heater and pump.
If any of the original wire supplied with the heater must
be replaced, it must be replaced with 105°C or its
equivalent.
Power is connected to the heater via the rear wiring
box as shown at the top of Fig. 19. Main heater power
is connected to terminals 1, 2 and 3 and pump power
is connected to terminals 4, 5 and 6.
Field wiring connections such as sensors, interlocks,
enable/disable and alarm contacts are made at the low
voltage terminal strip at the front of the heater as
shown at the bottom of Fig. 19.
Field-Connected Controllers
It is strongly recommended that all individually-pow-
ered control modules and the heater should be
supplied from the same power source.
Gas Supply Pressure
A minimum of 4.0 in. WC and a maximum of 10.5 in.
WC upstream gas pressure is required under load and
no-load conditions for natural gas. A minimum of 4.0
in. WC and a maximum of 13.0 in. WC is required for
propane gas. If upstream pressure exceeds these val-
ues, an intermediate gas pressure regulator, of the
lockup type, must be installed.
When connecting additional gas utilization equipment
to the gas piping system, the existing piping must be
checked to determine if it has adequate capacity for
the combined load. The gas valve pressure regulator
on the heater is nominally preset as noted in Table K.
During normal operation, carbon dioxide should be 8.5
to 9.0% at full fire for natural gas and between 9.5 and
10.0% for propane gas. Carbon monoxide should be
‹100ppm.
Electrical Power Connections
Installations must follow these codes:
•
National Electrical Code and any other national,
state, provincial or local codes or regulations hav-
ing jurisdiction.
Natural Gas – 1,000 BTU/ft
3
, 0.60 specific gravity at 0.5 in. WC pressure drop
Propane Gas – 2,500 BTU/ft
3
, 1.53 specific gravity at 0.6 in. WC pressure drop
Table J: Maximum Equivalent Pipe Length
NOTE: Manifold pressures should be ±0.2 in. WC.
Table K: Manifold Gas Pressure Settings
Model No.
Manifold Gas Pressure
(High Fire Values)
Natural Gas
Propane Gas
1005
-1.1
-0.6
1505
-1.6
0.3
2005
-1.8
-2.0
Model
No.
1-1/4” NPT
1-1/2” NPT
2” NPT
2-1/2” NPT
N
P
N
P
N
P
N
P
1005
35
55
35
90
125
300
300
1505
10
15
15
25
60
150
150
275
2005
35
90
85
210
California Hot Water Supply, Inc.
(800) 249-7244
20
