Table of Contents
Advertisement
Wiring
ELECTRIC SHOCK HAZARD.
power before installing or servicing heater.
Failure to do so could result in personal injury
or property damage. Heater must be installed
or serviced by a qualified person in accordance
with the National Electrical Code, NFPA 70.
ELECTRIC SHOCK HAZARD.
involving electric heaters must be performed
by a qualified person and must be effective-
ly grounded in accordance with the National
Electrical Code to eliminate shock hazard.
1. Connect heater only to the voltage, frequency and
phase specified on the nameplate.
2. All wiring should be done according to local and
National Electric Codes.
3. Make supply connections to marked heater termi-
nals using wire suitable for 75°C. (Type RH-RW or
equivalent). In addition, the supply wires must be
rated to supply a minimum of 125% of the total am-
perage load required by the Duct Heater.
Field Wire/Conduit Sizing (based on 125% of total heater amperage)
1PH
120
208
240
1.4
2.5
2.9
1.8
3.1
3.6
2.5
4.4
5.0
3.8
6.7
7.7
4.7
8.1
9.4
6.1
10.6
12.2
7.2
12.5
14.4
8.3
14.4
16.6
9.4
16.2
18.7
10.8
18.7
21.6
12.6
21.8
25.2
14.4
25.0
28.8
16.6
28.7
33.1
18.4
31.8
36.7
20.5
35.6
41.0
22.3
38.7
44.6
24.1
41.8
48.2
27.4
47.4
54.7
30.2
52.4
60.5
33.1
57.4
66.2
35.3
61.2
70.6
Disconnect all
Any installation
3PH
277
208
240
3.3
4.3
5.0
4.2
5.4
6.2
5.8
7.6
8.7
8.9
11.5
13.3
10.8
14.1
16.2
14.1
18.4
21.2
16.6
21.6
24.9
19.1
24.9
28.7
21.6
28.1
32.4
24.9
32.4
37.4
29.1
37.8
43.6
33.2
43.2
49.9
38.2
49.7
57.4
42.4
55.1
63.6
47.4
61.6
71.1
51.5
67.0
77.3
55.7
72.4
83.6
63.2
82.1
94.8
69.8
90.8
104.8
76.5
99.4
114.7
81.4
105.9
122.2
4. Connect field wiring to the Duct Heater using the
Wiring Diagram provided with the heater.
5. Conduit attachment to heater:
a. Ensure that conduit size used matches the
knock-out size(s) provided on Duct Heater
b. Run conduit(s) to conduit knock-out(s) on Duct
Heater
c. Remove knock-out(s) with a punch and hammer.
d. Install conduit to knock-out hole.
6. If the heater does not include a main circuit breaker
or a disconnect switch, a remote disconnect must
be provided (see N.E.C. 424.65).
7. Any wiring that is connected to the secondary
(control) wiring of the Duct Heater is required to be
N.E.C. class 1 (see National Electric Code, Article
725).
Wiring Diagram
The appropriate wiring diagram will be supplied with
each heater.
Wire Size
(AWG or
480
kcmil)
10.0
14
12.5
12
17.5
10
26.6
8
32.4
6
42.4
4
49.9
3
57.4
2
64.8
1
74.8
1/0
87.3
2/0
99.8
3/0
114.7
4/0
127.2
250
142.2
300
154.6
350
167.1
400
189.6
500
209.5
600
229.5
700
244.4
800
10
Conduit Size
Heater
1ph
3ph
Amps
1/2
1/2
12
1/2
1/2
15
1/2
1/2
21
1/2
3/4
32
3/4
3/4
39
3/4
1
51
1
1
60
1
1-1/4
69
1-1/4
1-1/4
78
1-1/4
1-1/2
90
1-1/4
1-1/2
105
1-1/2
2
120
2
2
138
2
2-1/2
153
2
2-1/2
171
2-1/2
2-1/2
186
2-1/2
3
201
2-1/2
3
228
3
3-1/2
252
3
3-1/2
276
3
3-1/2
294
Advertisement
Table of Contents
