CCI Thermal Technologies DIT - Insert Air Duct Heater (Non-Finned Tubular Elements - Calrod type*) - Manuel (Page 2)

CCI Thermal Technologies Inc. 2767 Brighton Road, Oakville, ON L6H 6J4 Tel. (905) 829-4422 Fax (905) 829-4430
www.ccithermal.com
MI123 REV.5 Page 2 of 2
Figure 5 - Air Velocity Requirements
3.2 Unless specifically indicated otherwise on the nameplate,
units must be installed in a horizontal duct with the terminal housing
at the side and limit controls at the top.
3.3 The duct heater must be installed in a manner that ensures
even air distribution across the face, and must be located away
from fans, sharp bends, or abrupt transitions.
3.4 If the duct heater is larger that the duct, use a duct transition
section as shown in Figure 6 below.
Figure 6 - Transition Section
3.5 The duct may require reinforcement to carry the added
weight of the duct heater.
3.6 INSERT TYPE DUCT HEATER
Make an opening in the duct at the selected location that is 1/
8” greater than the height and width of the heater. Install the
heater and secure it to the duct with sheet metal screws through
the angle iron of the terminal enclosure (see Figure 7).
Figure 7 - Insert Type Installation
3.7 FLANGE TYPE DUCT HEATER
Cut a section out of the duct that is 4” less than the width of the
heater. Fold up the sheet metal to form 2” wide flanges on the
three sides shown in Figure 8. Install the heater and secure it to
the flanges using sheet metal screws or bolts.
Figure 8 - Flange Type Installation
3.8 If the duct is being insulated, DO NOT INSULATE over
the heater terminal box and any associated control housing as
this may lead to overheating of the terminals and wiring.
3.9 Use qualified personnel to connect the power (and control
wiring if applicable) to the heater as indicated on the electrical
schematic enclosed in the terminal enclosure. Use at least 90°C
rated wire. Disconnecting means, overcurrent protection,
conductor sizing, etc. must conform to local electrical codes.
4.0 OPERATION
4.1 To ensure long heater life, it is very important to maintain
air flow at or above the minimum air flow indicated on the
nameplate.
4.2
Duct heaters are designed to operate with a maximum air
inlet temperature of 25°C(77°F).
4.3
If, during operation, a high limit trips, check the fan system,
louvre openings, temperature control settings and air distribution
across the heater face prior to re-energizing.
The manual reset limit can only be reset after it has had time to
cool. NEVER bypass the high limits with a jumper wire or other
means, since you may create a fire hazard or damage the heater.
5.0 MAINTENANCE
5.1 One week after initial installation, visually inspect the heater
and check all accessible electrical connections for tightness. Be
on the look-out for signs of overheating.
5.2
Prior to starting the heater after an extended shutdown
(i.e. for the summer); check the insulation resistance. Values
below 500kΩ indicate that moisture has been absorbed.
Extremely low values will result in fuse failure due to the high
inrush current at startup. To correct this situation, operate the
heater at reduced voltage for approximately 24 hours to dry the
elements.
T
OT
AL
KILOW
A
TTS PER SQ.FT
.
MINIMUM AIR VELOCITY (FPS)