ENVISION CONSOLE INSTALLATION MANUAL
Envision Console Controls
-MS/TP @ 19,200 Baud rate
-Limit devices to 40 on a single trunk line.
Control and Safety Feature Details
Emergency Shutdown
The emergency shutdown mode can be activated by a command from a facility management system or a closed contact on
Lockout Mode
Lockout mode can be activated by any of the following fault signals: refrigerant system high pressure, refrigerant system low pressure, water coil low temperature (freeze sensing), and condensate overflow. When any valid fault signal remains continuously active for the length of its rec- ognition delay, the controller will go into fault retry mode, which will turn off the compressor. After the Compressor short cycle delay, the compressor will attempt to operate once again. If three consecutive faults occur in 60 minutes during a single heating or cooling demand, the unit will go into lockout mode, turning off the compressor, enabling the alarm output, and setting the fan back to low speed operation until the controller is reset. If the control faults due to the low pressure input
Water Coil Low Temp (Freeze Sensing) Limit (AI-5)
The water coil low temperature (freeze sensing) limit sen- sor will monitor the liquid refrigerant temperature enter- ing the water coil in the heating mode. If the temperature drops below the water coil low temperature (freeze sens- ing) limit trip point for the recognition delay period, the condition will be recognized as a fault. The water coil low temperature (freeze sensing) limit trip point will be factory set for 30°F and will be field selectable for 15°F by remov- ing a jumper wire on
High Pressure (BI-11)
The
Low Pressure (BI-3)
The
Condensate Overflow
The condensate overflow sensing circuit will monitor the condensate level as a resistance input to
Alarm Output (BO-6)
The alarm output will be enabled when the control is in the lockout mode and will be disabled when the lockout is reset.
Test Mode
Raising the zone temperature input
Sequence of Operation
Power Fail Restart
When the controller is first powered up, the outputs will be disabled for a random start delay. The delay is provided to prevent simultaneous starting of multiple heat pumps. Once the timer expires, the controller will operate normally.
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