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ETM’s:
8/15/96
Subject: “Heat Pump” ETM’s and Controllers
The ETM-1030 the
ETM-3010D, and the UVC-5 were initially designed for water source heat pump
applications. They contain a
feature called “compressor delay” that delays energizing the compressor
upon a call for cooling. This
allows a network sequence time to bring on a water loop circulating pump
before the compressor is energized.
There is not a specific output in these modules for a reversing
valve. This must be addressed in
the heat pump’s control panel.
06/25/97
Subject: Resetting Unitary
Controller Run Times
With Unitary
Controllers (ETM, UVC, etc.) the
only way to reset the run times of all the outputs is to make the
controller dial out a maintenance interval. This can be done by entering a “1” for the maintenance
interval. Then it will dial in and
report a Maintenance alarm at the next dial out time that is specified in
the communication parameters screen.
After it has done that, you should go back and reset the maintenance
interval to what it was before.
When you do a download, and make the
choice to “Initialize” run times, this will reset the fan run time to zero,
but will not reset the other outputs.
Also, at the accumulated run time log you can reset the run times,
but again this will only reset the fan run times.
8/15/96
Subject: ETM Damper Control
and Sensor Failure Modes.
Within the ETM
family of modules, there are a few variations of damper control and sensor
fault operations:
Damper control -
for the ETM-1010 with PROM version 3.5, ETM-2020, 2024, and 2040: Damper control - during scheduled ON
time the damper will open and close around the midpoint between the heating
and cooling setpoints. For other
ETM types, and all types during scheduled off time, when the cooling
setpoint is reached, the damper will operate for 5 minutes, then if it is
still above the cooling setpoint the cooling output will energize.
Sensor fault -
The ETM-1010, 1020, and 1030, will bring on the heat with an open sensor
and the cooling with a shorted sensor.
The ETM-2010 will turn all outputs Off with an open or shorted
sensor.
The ETM-2024,
2020, and 2040 modules have user definable sensor fault modes (heat, cool,
or off) when the sensor goes open or shorted. This is parameter #37 on it’s control settings.
All sensor
faults generate a critical alarm, which should call out immediately.
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