Comfort Heating System Provides Remote Control Advantages And High-Limit Protection


A German ship manufacturer required comfort heating for a new oceangoing vessel. Protection from overheating and corrosion were the main requirements for the heating system


Because they provide even, consistent heating as well as long life, Watlow duct heaters were recommended. Watlow designed a 70KW heater rated at 380 volts for the system.

A flange-mounted disconnect mechanism was installed to shut off power to the heater. Distribution blocks power individual heater circuits to facilitate ease of wiring.

Watlow designed a control panel rated for NEMA 4X resistance to water and corrosion. Operating inside the control panel is a SERIES 965 temperature control with NEMA 4X rating, four mercury relays and a SERIES 140 high-limit controller to protect from overheating.

A control relay operated from a remote location prevents the controls from energizing unless the blower fan is on. This ensures that the heaters will only be turned on when air passes across the elements, thus eliminating possible heater failures.