Thermolec Application &Technical Notes - Manual (Page 43)

S
PECIFICATION FOR
TUBULAR HEATERS
Long Form
Supply where indicated in these specifications CSA (NRTL/C) approved tubular duct heaters as manufactured by
THERMOLEC.
☛ 1- CONSTRUCTION:
• Frame shall be corrosion-resistant and made of galvanized steel of suitable gauge as required by CSA.
• 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.
☛ 2- SAFETY CONTROLS:
• Heaters shall be equipped with fail-safe automatic reset disc-type thermal cut-out(s) located in the top frame
component above the heating elements.
• In addition to the automatic reset cut-out, heaters of 30 KW and less, rated for voltages below 300 volts shall be
equipped with a fail-safe manual reset disc-type thermal cut-out, semi-recessed in the terminal box, facing the
heating element hairpin as required by CSA.
• The sensing element of the cut-out shall be stream mounted, shall be shielded from mechanical damage and shall
face the center portion of the heating section so as to make the heater non-sensitive to air flow direction.
• Cut-outs shall de-energize the heater in case of insufficient air flow.
• For maintenance and safety purposes, a built-in disconnect shall be supplied to switch the power off at the heater
location.
• Load fuses shall be supplied as required by NEC (National Electrical Code).
☛ 3- AIR FLOW:
• Duct heaters shall be non-sensitive to air flow direction and interchangeable for horizontal or vertical ducts.
☛ 4- MOUNTING METHOD:
• Heaters shall be ST slip-in type or model FT flanged type, as shown on the plans or on the heater schedule.
• Slip-in 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.
• Flanged heaters shall be suitable for attaching to matching flanges on the duct.
• Mounting flanges on both models shall be independent of the terminal box so as to allow installation without opening
the box or drilling into it.
☛ 5- SIZE & CAPACITY:
• Heater size, volts, phase kilowatt and number of control stages shall be as per heater schedule.
TUBULAR HEATER SPECIFICATION
THERMOLEC