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ECO-Y INSTALLATION MANUAL
Standard Microprocessor
Flexible Control Options
The standard control system is a microprocessor-based printed
circuit board, (PCB), conveniently located in the unit control box for
accessibility. The microprocessor control is specifically designed for
geothermal water source heat pumps to integrate compressors and
advanced features needed in geothermal water source heat pump
applications. The microprocessor provides control of the entire
unit as well as outputs for status modes, faults, and diagnostics.
Low voltage thermostat terminal strips provide convenient field
connections. LEDs are located in the corner post to assist the
technician when servicing the unit.
Startup
The unit will not operate until all the inputs and safety controls are
checked for normal conditions. At first powerup, a five minute delay
is employed before the compressor is energized.
Component Sequencing Delays
Components are sequenced and delayed for optimum space
conditioning performance.
Short Cycle Protection
The control allows a minimum on time of 2 minutes and a minimum
off time of 5 minutes for short cycle protection.
Condensate Overflow Protection
The control board incorporates an impedance
sensing liquid sensor at the top of the drain pan. Upon
a continuous 30-second sensing of the condensate,
compressor operation is suspended (see Fault Retry), and
the condensate overflow lockout LED begins flashing.
Safety Controls
The control receives separate signals for a high pressure switch
for safety, a low pressure switch to prevent loss of charge damage,
and a low suction temperature thermistor for freeze sensing. Upon
a continuous 30-second measurement of the fault (immediate
for high pressure), compressor operation is suspended, the
appropriate lockout LED begins flashing. (Refer to the “Fault Retry”
section below).
Testing
The control allows service personnel to shorten most timing delays
for faster diagnostics.
Fault Retry
All faults are retried twice before finally locking the unit out.
An output signal is made available for a fault LED at the
thermostat. The “Fault Retry” feature is designed to prevent
nuisance service calls.
Diagnostics
The control board allows all inputs and outputs to be displayed on
the LEDs for fast and simple control board
diagnosis.
Emergency Shutdown
A grounded signal to common or connecting 24 VAC to the ES
terminal places the controller into the emergency shutdown mode.
The compressor and blower operation are suspended while in the
emergency shutdown mode.
Heating Operation
Heating (Y1)
The blower motor is started immediately after the “Y1” input is
received, and the compressor is energized 10 seconds after the
“Y1” input.
Heat, 2
nd
Stage (Y1, Y2) X13 ECM
When the gray wire is connected to the motor (Y2 is field
connected) the blower speed will increase.
Heat, 3
rd
Stage (Y1, Y2, W) X13 ECM
When a "W" input is received the blower speed will increase and
all stages of resistance heat will be energized along with the
compressor operation.
Emergency Heat (W only)
The blower is started on high speed and all stages of resistance
heat are energized.
Cooling Operation
In all cooling operations, the reversing valve directly tracks the “O”
input. Thus, anytime the “O” input is present, the reversing valve
will be energized.
Controls