Initial Power On
When power supply is connected to the iRC for the first
time, a series of inputs is required to identify specific
system parameters. Since there are no factory set-point
defaults pre-setup, the Quick Set-up procedure is triggered
to capture essential information about the system when
the system is first energized. This also occurs when a new
iRC board is installed on a single evaporator system.
Inputs for the Quick Set-up are made using the iRC user
interface (UI) control. The Control Knob on the iRC UI is
used to navigate through the required steps and to identify
selections. Turning the knob will navigate through pos-
sible selections for that particular parameter. Pressing the
Control Knob makes selections (similar to an Enter key on
a PC).

System Start-up

When the system is initiated for the first time, the compres-
sor and the electric defrost evaporator fans will be in a
hold-off cycle and will not start unless the hold-off cycle is
complete. The electric expansion valve (EXV) then opens
to 50% and will begin its superheat control sequence. The
compressor starts and will be in a "hold-on" cycle. (This is to
minimize short-cycling of the system).
 

At initial start-up, the system may cycle off after a few
minutes and display a low superheat error, then restart itself.
This cycle may be repeated a few times. Do not shut the sys-
tem off. Let the system run, as it may take a few cycles for
the electric expansion valve to attain the correct setting for
the set superheat.
 

Do not leave the unit unattended until the system has
reached normal operating conditions with the box pulled
down to design conditions and the oil charge has been
properly adjusted to maintain the oil level at the center of the
sight glass.
 

When the room thermostat setting is satisfied (which may
take a considerable amount of time on “hot-box” pulldown),
and if the compressor has run for a minimum time for the
“hold-on” cycle, the EXV will close (shutting off the refriger-
ant flow to the evaporator), and the system will pumpdown
and shut off. The evaporator fans will continue to run.

Call for Cooling Start-up Operation

When the box temperature sensor detects a rise of approxi-
mately half the box temperature differential, and the system
has been off a minimum of the hold-off cycle time, the EXV
will open to its last position, and the compressor will start.
The EXV is then adjusted as necessary to obtain and main-
tain the superheat setting. During this time, the compressor
will run for a minimum of the “hold-on” cycle time.

Monitor Menu List: