MIL-PRF-22594C(SH)
3.12.2 Protection for heater. Each heater shall be provided with a manual reset high limit cutout switch that
will limit the surface temperature of the heating elements to 750 °F or less with no airflow. Cutout switch shall be
suitable for pilot duty at 115 volts alternating current. The high limit switch shall have a provision for manual reset
from the exterior of the enclosure for the electrical connections.
3.12.3 Kilowatt rating. The kilowatt rating of a specific size and type heater shall be equal to that specified in
table II ±5 percent, based on 10 ºF DB temperature air entering the heater air inlet at rated airflow.
3.12.4 Resistance to airflow. The maximum resistance to airflow through a heater shall be 0.35 inch of water at
rated airflow at standard conditions as defined in 3.11.1.
TABLE II. Kilowatt rating.
Size
Capacity in kilowatts (kW)
Type L
Type M
Type H
19EH
-
-
0.5
20EH
-
0.58
1.0
21EH
0.65
1.26
1.9
22EH
1.0
1.93
2.9
23EH
1.52
3.0
4.5
24EH
1.90
3.74
5.5
25EH
2.90
5.72
8.5
26EH
4.59
9.1
13.5
27EH
6.76
13.4
20.0
28EH
9.26
18.3
27.3
29EH
12.3
24.3
36.2
30EH
15.3
30.2
45.0
31EH
17.2
33.9
50.5
32EH
18.2
36.0
53.8
33EH
23.5
46.4
69.2
34EH
28.5
56.3
84.0
35EH
33.9
67.1
100.0
36EH
39.7
78.4
117.0
37EH
50.9
100.6
150.0
38EH
61.9
122.4
183.0
3.12.5 Heater electrical circuits.
3.12.5.1 Circuit strength. Heater electrical circuits shall be subjected to and shall withstand for a period of
1 minute, a dielectric test voltage of twice the rated line voltage plus 1,000 volts applied between each electrical
circuit and the frame with all other electrical conductor and metal parts grounded. The voltage wave shall
approximate a sine wave, and frequency shall be 60 Hertz or greater (see 4.5.5.4).
3.12.5.2 Insulation resistance. The insulation resistance of the assembled heater at operating temperature shall
be not less than 5 megohms (see 4.5.5.5).
3.12.6 Heater creepage and clearance. Creepage shall be equal to or greater than ¼ inch and clearance shall be
equal to or greater than ⅛ inch.
8
For Parts Inquires call Parts Hangar, Inc (727) 493-0744
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business