WarmlyYours SCP-120 - Manual (Page 3)

High Limit Sensor
The calibrated 40°F to 90°F (4°C to 32°C) high limit sensor prevents excessive temperatures
when using constant wattage and MI heaters. It also permits safe testing at outdoor temperatures too
high for continuous heater operation. The temperature sensor is included.
There are two DIP switch confi gurable operation modes for the high limit thermostat. The fac-
tory default operation mode uses the high limit thermostat as a slab temperature regulator, preventing
heater operation at temperatures above the set HIGH TEMPERATURE LIMIT. The optional operation
mode uses the high limit thermostat as an ambient air sensor, preventing heater operation at temper-
atures above the set HIGH TEMPERATURE LIMIT until the temperature comes back within limits.
The details of operation in each mode are as follows:
Slab Regulating Thermostat Mode
• High temperature causes unit to turn off heaters, if running, and to ignore any call for heater
operation from the panel, RCO or EMC.
• High temperature continues any hold-on cycle that was initiated before the high temperature
condition. If the slab temperature drops within limits during the hold-on time the heater will be turned
back on.
• The HEATER CYCLE functions normally.
Ambient Temperature Sensor Mode
• High temperature causes unit to turn off heaters, if running, and to ignore any call for heater
operation from the panel, RCO (RCU) or EMC.
• High temperature cancels any hold-on cycle that was initiated before the high temperature
condition.
• If the HEATER CYCLE switch is operated in a high temperature condition the heater(s) will be
turned on for a maximum of 30 seconds. A new HEATER CYCLE can not be initiated for another two
minutes after that.