- 10 -
1) Set Point
Rotate the circular selector in correspondence with the arrow placed nearby. The
selector represents -33°F to 50°F (-35°C to +10°C) for low temperature models,
and 14°F to 68°F (-10°C to +20°C) for medium temperature models. “10” is the
coldest setting, “1” is the warmest.
2) Differential
It is possible to modify the differential from 1°F minimum to 12.5°F maximum.
Simply shift the first two dip-switches to the ON or OFF position according to the
wanted value.
3) Defrost management and setting
A defrost can be activated manually, by pressing the “man. def.” button, or
cyclically, the interval set by the “def.intvl” rotary switch at the top left with respect
to Set Point selector. The interval can be selected from 1 to 12 hours in 1 hour
steps. If the selector is positioned on the “0”, the cyclic defrost is disabled.
Note:
manual defrost reinitializes the time required for successive cyclic
defrosting. The selections are effective beginning from the successive cycle. For
an immediate effect, it is necessary to turn power to the UniStat off for a few
seconds.
It is possible to choose between an electric defrost (the compressor is
deactivated and the defrost relay is activated) and a hot gas defrost (both the
compressor and the defrost relay are activated); The defrost termination, can
take place by time (from 1 to 60 min.) or by temperature (from 0 to 86°F) if the
defrost sensor is utilized for the correct programming). If the defrost sensor is
disconnected, interrupted or breaks down for any reason, the defrost terminates
after a maximum time of 90 minutes if it is resistance-based, or 40 minutes if it is
hot-gas based.
The instrument stores the defrost state every 15 minutes to allow restart after
power loss.
4) Compressor safety function
If the function is enabled, a minimum three minute interval is ensured between
deactivation and successive restart of the compressor.
If the function is enabled, the compressor is not energized for three minutes after
controller power up.
The function is also active in hot-gas defrost mode.
