ELECTRIC HEAT HOLD-OFF (See Figures 13 and 14)

In other applications, it is desirable to disable the operation of the electric heat until outdoor temperatures have reached a certain design point. This won't allow the electric heat to come on as second stage heating unless the outdoor temperature is below the set point of the outdoor thermostat. This is done to maximize

efficiency by utilizing the heat pump to bring the conditioned space temperature up, rather than cycling on the electric heat due a second stage call for heat from the thermostat on start-up coming off a night setback condition or someone increasing the thermostat set point. (NOTE: Some programmable thermostats do have a built-in time delay for pulling in second stage heat when coming off setback conditions.)

FIGURE 13

ELECTRIC HEAT HOLD-OFF WIRING 4 & 10KW 1 PH — 6 & 9KW 3 PH

FIGURE 14

ELECTRIC HEAT HOLD-OFF WIRING

15KW 1 PH & 3 PH

Manual

2100-193O

Page

18 of 26

Page 18
Image 18
Bard WH-301, WH361 Electric Heat HOLD-OFF See Figures 13, Electric Heat HOLD-OFF Wiring 4 & 10KW 1 PH 6 & 9KW 3 PH