Electrical power connections – Raypak 503-2003 User Manual
Page 20
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The MVB 503-1503 heaters are wired for 120 VAC, 12
amps while the MVB 1753 & 2003 heaters are wired
for 120 VAC, 18 amps. Consult the wiring diagram
shipped with the heater. Before starting the heater,
check to ensure proper voltage to the heater and
pump.
Boiler mounted pumps (up to
3
⁄
4
hp) get their power
supply directly from the boiler power supply (connec-
tions in rear wiring box). Install a circuit breaker sized
sufficiently for both the heater and the pump. Pumps
larger than
3
⁄
4
hp must use a separate power supply
and run the power through the optional pump contac-
tor which is located in the rear wiring box. Use
appropriately-sized wire as defined by NEC, CSA
and/or local codes. All primary wiring should be 125%
of minimum rating.
If any of the original wire as supplied with the heater
must be replaced, it must be replaced with 105°C wire
or its equivalent.
All field wiring connections to the MVB heater are
made inside the rear wiring box as shown in Fig. 16.
Pump power should be taken from terminals 2 (Com),
3 (GND) and 6 (Hot) –
3
⁄
4
hp and smaller ONLY. Power
to the MVB heater should be connected to terminals 1,
2, and 3 as noted in Fig. 16. Sensors, interlocks,
enable/disable, and various options are wired into ter-
minals 1–12 as noted in Fig. 16.
The gas valve pressure regulator on the heater is
nominally preset as noted in Table I.
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.
•
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.
1” NPT
1-1/4” NPT
1-1/2” NPT
2” NPT
2-1/2” NPT
Model
No.
N
P
N
P
N
P
N
P
N
P
503
15
35
65
150
130
360
N/A
N/A
N/A
N/A
753
5
15
65
100
75
180
250
N/A
N/A
N/A
1003
N/A
N/A
35
55
35
90
125
300
300
N/A
1253
N/A
N/A
15
25
25
60
85
225
200
300
1503
N/A
N/A
10
15
15
25
60
150
150
275
1753
N/A
N/A
N/A
N/A
N/A
N/A
45
110
115
230
2003
N/A
N/A
N/A
N/A
N/A
N/A
35
90
85
210
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 H: Maximum Equivalent Pipe Length
Manifold Gas Pressure
(High Fire Values)
Model
No.
Natural Gas
Propane Gas
503
-0.1
-0.1
753
-0.4
-0.1
1003 -0.8
-0.2
1253 -1.6
-0.2
1503 -2.4
-0.6
1753 -0.4
-0.1
2003 -1.0
-0.5
NOTE: Manifold pressures should be ±0.2 in. WC.
Table I: Manifold Gas Pressure Settings