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HOW TO DESIGNATE A MODEL:
Duct Heater Series
Control Box Options
3 = Control Box on Heater, R = Remote
Duct Width Dimension
(over 55” heater must be flanged)
Duct Height Dimension
Kilowatts
Power Supply Volts
Phase
1 = Single Phase, 3 = Three Phase
Air Flow Direction
Internal Duct Insulation
0 = None, 1 = 1” Thick, 2 = 2” Thick
Control Volts
24, 120, 240, & 277
Number of Control Stages
Construction Options
F = Flange Mount, I = Insert
CHMS 3
I
18W 12H 15KW 480
3
24
2
HL 1
CHMS Series Finned Tubular Element Duct Heater
Finned tubular duct heaters provide many benefits to the customer. They provide slower heating and cooling for closer temperature
regulation, electrical shock hazards are reduced, not as susceptible to shorting on the elements, are easily serviced, and better
withstand physical abuse.
Product Specifications
General
1. Provide Series “CHMS” enclosed element electric duct heaters as manufactured and listed on schedule.
2. Power, voltage phase, control voltage, wattage, duct size, number of steps to be per schedule.
3. Heaters to be either slip-in or flanged type as called for on schedule.
4. All heaters to be ETL listed for zero clearance to combustible surfaces and bear ETL label.
5. All heaters shall meet the requirements of the National Electric Code.
6. Standard terminal box, recessed terminal box, standard control cabinet, remote control cabinet and
element housing to be made of 18 gauge aluminized steel.
Element Construction
1. All elements to be made of high quality alloy resistor wire, centered and permanently encased within highly
compacted, rock-hard refractory material, surrounded by stainless steel sheath. All element terminations
shall be threaded stainless steel type to insure a positive connection to leads.
Terminal Box or Control Cabinet
1. Shall be constructed of 18 gauge Aluminized steel. All boxes to have a solid cover of the same gauge,
complete with a piano type hinge on the longest dimension, tool operated latch and pull ring.
Safety Controls
1. Primary over temperature protection shall be provided by built-in capillary type automatic reset thermal
cutout. Capillary cutout shall be U.L. listed and of the fail safe type.
2. Secondary over temperature protection shall consist of a sufficient number of capillary type manual resets
controlling back-up contactors. Capillary shall be the “fail safe” and “trip free” type.
3. All capillaries shall be installed in a protective Aluminum sheath. Sheath shall be etched and painted flat
black to sense any over temperature condition the full length of heater face.
4. Over-current protection incorporating fuses must be provided for all heaters rated more than 48Amperes,
and factory installed, within the heater enclosure or provided as a separate assembly by the heater
manufacturer. Heaters exceeding 48 Amperes total line current must be divided into sub-circuits of less
than 48 Amperes and be protected at not more than 60 Amperes.
Wiring Diagrams
1. A separate, complete and specific wiring diagram shall be permanently attached to each heater. Typical
wiring diagrams are not acceptable.
2. Control and line terminals in each heater shall be marked to correspond to the wiring diagram.
MINIMUM HEATER SIZE 8” X 8”
MAX KW 18.1 KW PER SQ. FT.
• Insert or Flanged construction
• Integral or remote control panels
• Available with Nema 4-4x-12 control panels
NOTE: All blanks must be filled in when
submitting an order to the factory.
• ABS type approved
Air Flow Designations Guide for CHMS Series Duct Heaters
HR: Left to Right (shown)
HL: Right to Left
VU: Vertical Up
Control panel standard is extended upstream and same height as duct. This can be altered to accommodate available space.
• Made in U.S.A.