Thermolec Open coil heaters - Manual (Page 3)

3.4 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 flow.
Unless otherwise specified, all Thermolec heaters operate horizontally or vertically with the airflow in either
direction. This unique feature allows the contractor maximum flexibility in installation and avoidance of problems.
(Please see drawings page 4)
3.5 Manual-reset thermal cut-out
This protection device is standard on all heaters of less than 300V and 30 KW and is optional on all other heaters.
Please check the auto-reset thermal cut-out BEFORE re-setting the manual thermal cut-out. If any defect has been
detected in the auto-reset thermal cut-out, it will be necessary to replace it before re-setting the manual-reset
thermal cut-out.
4- 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:
4.1 Visual Inspection.
THERMOLEC strongly recommends a periodic inspection. This precautionary step will help to keep your installation
operating well. Note these eventual first 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.
4.2 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 first four months of operation. After that, two
inspections per heating season are sufficient.
4.3 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
4.4 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 infiltrating 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.