THERMOLEC H4R 1L1 Electric Heating and Controls Instruction Manual
- June 13, 2024
- THERMOLEC
Table of Contents
THERMOLEC H4R 1L1 Electric Heating and Controls Instruction Manual
Mechanical Installation of THERMOLEC heaters
Handling
- Remove the shipping covers just before installation.
- Inspect the heater carefully and report any damage to the manufacturer.
DO NOT INSTALL A DAMAGED HEATER
Installation
Heater Position
The axis of the duct must always be perpendicular to the face of the heater.
The air direction may be either vertical or horizontal, but when the unit is installed horizontally, the thermal cut outs must be on top.
Heaters with SCR controls are not made for universal installation. Follow the label on the heater for proper installation. Should there be any confl icts, contact Thermolec before installing the heater.
The heater can not be installed in an attic.
Model SC or ST (Slip-in type) (Please see drawings page 4).
Cut an opening in the side of the duct.
6 Slip the heater into the duct until the hole is completely covered by fl anges around the heater.
Fasten the heater to the duct with sheet metal screws and seal openings with a suitable sealing compound.
If the heater is heavy, use additional hangers to support the heater.
Model FC or FT (Flanged type) (Please see drawings page 4).
Flange both ends of the duct outwards on three sides to match the heater’s fl anges.
Fasten the heater to the duct with sheet metal screws. (For heavy heaters, use nuts and bolts and additional hangers to support the heater).
Seal openings with a suitable sealing compound.
Spacing Requirements to obtain Optimal air distribution over the heating elements of duct heaters are: (Please see drawings page 4).
Note: Distances may vary for heaters installed in air handling units (AHU)
• 24 inches between the heater and fi lter frame
- inches between the heater and elbows in the duct.
- inches between the heater and branches in the duct.
- inches between the heater and sharp transitions of the duct.
- = minimum distance = the largest of two dimensions (W or H) up to 48”.\
48 inches between the heater and a double outlet fan, except with split duct design.
30 inches between the heater and access doors or diffusers, except if a metal screen is supplied with the heater.
1 inch between the duct at the outlet side and combustible materials for a length of 72”, for vertical ducts only.
For the fl anged type, 24 inches between the control box cover and obstructions to allow space for installation and service.
For the slip-in type, width of the duct (dimension W) + depth of the control box + ten (10) inches between the control box cover and obstructions to allow slipping the heater out the duct and to allow safe servicing.
Important Notes
- Do not install a duct heater in a vertical duct directly above a ceiling diffuser or an opening in the ceiling.
- Do not install standard heaters outdoors. Order a heater with weatherproof control box instead.
- Do not install spray humidifi ers upstream of duct. Install it downstream instead.
- Do not cover the control box with thermal insulating materials.
- Use special air intake louvers of weatherproof construction for preheat duct heaters to avoid intake of water or snow
particles Make sure that motorized damper blades are not blocked with snow or dirt. Inspect the dampers regularly to ensure a suitable airfl ow.
Electrical Installation of THERMOLEC heaters
Disconnect all power sources before opening the control box and working within.
Read the nameplate carefully and consult wiring diagram before starting to wire.
Supply wires:
Use only wires suitable for 75°C. Wires shall be sized according to the Canadian Electrical Code requirements. All wires must be brought in through knock-outs.
Disconnecting means:
Install a disconnect switch close to the heater according to the code unless a disconnect switch is already built into the heater.
Control circuit wiring: Use class 2 wiring for control circuit connections to the duct heater
Magnetic contactors:
If magnetic contactors are mounted outside of the duct heater, use only
contactors approved for:
- 250,000 operations when controlled by auto-reset thermal cut-out (A) and by other switching devices in series with this cut- out (thermostat, step controller, air fl ow switch, etc.).
- 100,000 operations when controlled by auto-reset thermal cut-out (A) alone.
- 100,000 operations when controlled by auto-reset thermal cut-out (A) plus manual reset cut-out in series.(A&M).
- 6,000 operations when controlled by manual reset cut-out (M) alone.
External Controls ratings:
Rating of external control devices shall be suitable for handling the VA
ratings as marked on the nameplate ,otherwise, a back-up relay must be used.
Air Flow Interlock:
Heaters are generally supplied with two extra terminals marked I C for fan
interlock or air sensing device connection. Remove jumper between terminals I
and C before connecting the fan interlock, Select a suitable air fl ow sensing
device of the differential pressure sensing type, with snap acting contacts. A
slow make, slow brake device may cause undue cycling and in some instances
chattering of the contactors. When fresh air dampers are used, make sure the
heater is properly interlocked to prevent it from being energized before the
damper is fully open.
Operating THERMOLEC Heaters.
Minimum air fl ow.
Air fl ow below the value indicated on the nameplate could cause overheating
and lead to the opening of the auto reset thermal cut-out and/or manual reset
cut-out. Any air fl ow switch should only be used to sense airfl ow or a
pressure differential and not as a primary control to start or stop the duct
heater.
Warning.
The air fl owing through the duct where the heater is installed shall not
contain any combustible particles, nor any flammable vapor or gas.
Air Temperature.
The air temperature of our standard duct heater should not exceed 27°C (81°F)
at the heater inlet and 66°C (151°F) at the outlet.
Minimum static pressure and air direction.
The heater is protected by a pressure differential switch. To keep the contact
of this switch closed, it is necessary to maintain a minimum total pressure of
0,07 inches of water for a constant fl ow. For proper installation follow the
instructions on the label located on the control panel of the THERMOLEC duct
heater.
Manual-reset thermal cut-out
This protection device is standard on all heaters Please check the auto-reset
thermal cut-out BEFORE starting the heater. If any defect has been detected in
the auto-reset thermal cut-out, it will be necessary to replace it before re-
settingthe manual- reset thermal cut-out.
Maintenance
All THERMOLEC heaters have been designed to operate long term without problems. Those responsible for equipment and maintenance should be aware of the following:
Visual Inspection.
THERMOLEC strongly recommends a periodic inspection. This precautionary step
will help to keep your installation operating well. Note these eventual fi rst
signs of problems: Accumulation of dust on the heating elements, signs of
overheating on the heater frame, traces of water or rust on the control box.
Electrical Inspection.
Two weeks after startup , all electric connections to contactors should be
checked and tightened. Prior to each heating season, check the resistance
between the heating elements and ground. It is also recommended to check the
electrical connections to heating elements, magnetic contactors, and main
power lugs. This inspection is recommended monthly during the fi rst four
months of operation. After that, two inspections per heating season are suffi
cient.
What are the checkpoints?
- Check all fuses
- Check the resistance to ground for each circuit
- Check the resistance phase to phase for each circuit
- Check the tightening of connections at all contactors and heating elements
- Check all contactors
Off-season maintenance
Where tubular heating elements are used, THERMOLEC strongly recommends that
you start the heating system from time to time. This precaution will prevent
moisture from infi ltrating through the terminal gaskets into the heating
element and accumulating in the insulating powder. Should a heater be shut off
for a long period, we recommend that you carefully check the resistance to
ground for each circuit.
It is important not to power a heater when too low a resistance to ground has
been measured.
Control components such as step controllers or modulating valves (SCR) should
be maintained and checked according to respective manufacturers instructions.
Any defective components should be replaced only with approved original parts.
Installation of the FLANGED type FC or FT
Installation of the SLIP-IN type SC or ST
Minimum recommended distance for safety and service for safety and service
Installation of Thermolec heaters
Limited Warranty
- THERMOLEC LTD guarantees it’s heater resistance elements against any defect in workmanship and material for a period of two years and other built-in components for a period of one year, starting from the date of shipment from it’s factory. This warranty is limited to equipment and components supplied by THERMOLEC LTD.
- Improper installation, misuse of this product, or repairs made by others without THERMOLEC LTD’s authorization, will void this warranty.
- THERMOLEC LTD will repair or replace without charge, in its factory or in the fi eld at its own discretion, the heater or part, which upon manufacturer examination, is considered to be defective.
- THERMOLEC LTD shall not be held responsible for damage or delay and shall not be held liable for any charges resulting from the removal or replacement of the allegedly defective heater.
- THERMOLEC LTD shall not be held responsible for any incidental or consequential damage or delay due to workmanship or material. No additional charge will be accepted for repair, replacement or modifi cation if prior written authorization was not obtained from THERMOLEC LTD
- Any control device or accessory, supplied with the heater, to be mounted or connected remotely, will only be guaranteed by the manufacturer per conditions stated in paragraph 5.
- Components supplied for repairs are guaranteed for the balance of the original warranty or 90 days, whichever is longer.
- All repairs made at THERMOLEC LTD’s factory after the warranty period, is guaranteed for 30 days from the date of the repair.