Bard SH261, Руководство по установке

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Manual 2100-409C
Page
16 of 25
ELECTRIC HEAT HOLD-OFF
(SEE FIGURES 11 AND 12)
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 set-back
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 set-back conditions.)
FIGURE 11
ELECTRIC HEAT HOLD-OFF WIRING
4 – 10KW 1 PH — 6 & 9KW 3 PH
FIGURE 12
ELECTRIC HEAT HOLD-OFF WIRING
15 – 20KW 1 PH & 3 PH