Thermolec Application &Technical Notes - Manual (Page 41)

Short Form
• Supply where indicated in these specifications CSA (NRTL/C when required) approved duct heaters as
manufactured by THERMOLEC.
• Coils shall be of High Grade Nickel-Chrome alloy and shall be insulated by floating ceramic bushings from the
galvanized steel frame. Coil terminal pins shall be stainless steel insulated by means of non-rotating ceramic
bushings.
• Heaters shall be model SC slip-in type, as shown on the plans or on the heater schedule. Heaters shall be
suitable for insertion into the duct through an opening on its side and shall have a flange for securing it to the duct
side. Mounting flanges shall be independent of the terminal box so as to allow installation without opening the box
or drilling into it.
• All duct heaters shall be equipped with fail-safe, automatic reset and manual reset disc-type thermal cut-outs, as
required by CSA.
• Cut-outs shall be shielded from accidental impact, and shall de-energize the heater in case of insufficient air flow.
• Duct heaters shall be non-sensitive to air flow direction and interchangeable for horizontal or vertical ducts.
Heaters shall be CSA approved for zero clearance in horizontal ducts.
• Duct heaters shall be equipped with magnetic contactors as required, 24 volts transformer, airflow sensor, …(room
thermostat, duct thermostat, SCR control, load fuses, solid state relays, mercury contactors, pilot lights, protective
screens, etc).
• For maintenance and safety purposes, the heater shall be equipped with a built-in disconnect to switch the power
off at the heater location (option X1) and protective screens on both sides (option MS).
• Load fuses shall be supplied as required by local codes.
• Duct heaters for VAV systems will be electronic modulating type “THERMO-V”, equipped with a
proportional controller to modulate the total heater load according to the temperature control signal and a
proportional electronic air flow sensor (non pressure dependent type) to modulate the heater capacity
according to the available air flow:
Maximum heating with normal air flow
Reduced heating with low air flow
No heating with no air flow
OPEN COIL HEATER
THERMOLEC