Make-Up Air Heaters Installation & Wiring

Electrical Source Power

• See nameplate for voltage rating, amp draw, and maximum watts
• 120V single-phase, 240V single-phase, or 208V three-phase - depending upon model and size
• 120V model has 8’ plug-in cord
• All other models, terminal block connections (copper wire only)
• Units above 10 kW include internal fusing

24-Volt Control

• External 24-volt source is required for operation
• Turn-on (on/off function) accomplished with the presence of 24-volt source
• System or external contact closure provides 24 volts to this unit
  • Pressure differential switch
  • Inlet damper end switch
  • Relay connected to blower motor, contact closure
  • Exhaust motor current switch contact
  • Thermostat, blower function “G” (parallel connection)
  • Temperature sensing thermostat (must also operate blower

Round Enclosure, Non-Blower Details

Insert Element Rack Details