Thermolec Application &Technical Notes - Manual (Page 45)

S
PECIFICATION FOR
TUBULAR HEATERS
Short Form
• Supply where indicated in these specifications CSA (NRTL/C when required) approved duct heaters as
manufactured by THERMOLEC.
• Heating elements shall be tubular type made of heavy gauge Incoloy 800 filled with compacted magnesium oxide
insulating powder.
Above 277 Volts or 30KW, each tube shall be of "U" type and shall be removable through the control box without
removing the heater from its ductwork.
• Heaters shall be ST 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 disc-type thermal cut-outs, automatic reset and manual reset 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.
• 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.
• Load fuses shall be supplied as required by local codes.
TUBULAR HEATER SPECIFICATION
THERMOLEC