Emerson Copeland Scroll Series, Manual

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© 2017 Emerson Climate Technologies, Inc.
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AE5-1377 R3
voltage range of 180-260 VAC along with a frequency of
47-63 Hz. The electronics control along with the power
board will function properly providing the range of
operating limits is in compliance!
7. Physical Dimensions
See Figure 2 .
8. Installation / Piping Instructions
See Figure 2 for overall dimensions of the units. It is
recommended that a clearance of 8 inches from the wall
(or the next unit) be maintained from the unit’s left and
rear panel whereas a clearance of 20 inches is to be
maintained from the unit's right, top and front panels.
Both service access and airflow have been considered
in making these recommendations. Where multiple units
are to be installed in the same location, careful
consideration for proper clearance needs to be given to
each individual unit.
Ideally, the unit should be mounted level on a solid
concrete slab with rubber strips between unit feet and
concrete. However, these units have been designed for
mounting on suitable brackets for wall mounting. In this
case it is equally important that the spatial guidelines
given above are followed, and additional consideration
needs to be given for possible air recycling if units are
stacked above and below each other. In general terms,
air by-pass around each condenser and between each
unit should be avoided at all times.
Pipe sizing should not only be of sufficient size to ensure
optimum performance and good oil return, but it also
needs to take into account the full capacity range
through which this particular unit will need to operate.
Follow the ASHRAE guidelines for proper piping
practices.
9. Condensing Unit Operational Control
The Digital Control electronic control board controls the
operation of the condensing unit. Whenever there is a
control input asking to start or stop the condensing unit,
the control board will execute a set of pre-programmed
procedures to do so. It also monitors the compressor
operating parameters, so as to protect the system from
unsafe operating parameters. See
Figure 3 .
For example, when the low temperature unit
experiences an extreme temperature day, the control
board
decides to switch from vapor-injection-
optimization to discharge gas temperature control to
allow the compressor to run safely and pass the extreme
weather hours.
10. Control Features
The base control function is for the following standard
features. See
Figure 3 for additional input options and
output options of the control board.
10.1. Fresh Start Program
This Fresh Start Program is a bump start procedure that
will energize and start the compressor for 3 seconds and
then will be followed by a 20 second off cycle time. This
will occur for 3 cycles, and then continuous power will
be supplied to the compressor for normal operation.
The Fresh Start Program will be executed on initial start
up or any time power is reapplied when the ambient
temperature is lower than 95°F. In addition, the Fresh
Start Program will be executed for any start when the
unit has been cycled off for more than an hour when the
ambient temperature is lower than 95°F.
10.2. Stop Program
When the unit is satisfied, or there is any error which
requires the unit to be shut down, the controller will
execute a Stop Program. The compressor and the
condenser fans will cycle off and the injection valves will
close.
For low temperature units only, when the unit is satisfied
the EXV will start closing immediately, but the
compressor will delay 5 seconds before shut down to
prevent reverse rotation of the compressor.
10.3. Automatic Liquid Injection (Medium
temperature units only)
Automatic Liquid Injection ensures that the scroll
compressor operates within a safe temperature limit.
This unit employs a patented liquid injection system
which injects a saturated refrigerant into the suction line
at the compressor. Activation of the liquid injection valve
is in response to a thermistor which is attached to the
compressor discharge line. A signal is sent to the
stepper motor of the injection valve, opening the valve
in response to increasing discharge temperatures and
injecting saturated refrigerant to reduce the discharge
temperature.
10.4. Compressor Phase Reversal
Compressor Phase Reversal senses for the correct
phase sequence on three phase applications. Reset is
automatic once the correct phase sequence is sensed.
An error message will be shown on the diagnostic LED.