The Markel PD Series Insert Duct Heaters are a standard packaged duct heating system.
Galvanized Steel Compartment with 1/2 Inch fiberglass Insulation and Hinged Cover.
Door Interlock Disconnect Switch.
Primary Automatic Reset Temp Limiting Control.
Load Carrying Secondary over Temperature Protective Device(s).
Definite Purpose Magnetic Contactor(s).
Differential Pressure Fan Interlock Switch.
Step Down Control Transformer 24VAC.
Permanently Attached Wiring Diagram on inside of Terminal Compartment Cover.
The galvanized steel element rack is designed to be 1 Inch shorter than duct height and 1/2 Inch shorter than duct width to allow insertion clearance.
Markel 4PD30162423 Packaged Insert Duct Heater Sales Bulletin