© Copyright 2018 KE2 Therm Solutions, Inc., Washington, Missouri 63090
Q.2.43 April 2018
Page 10
KE2 Compressor
Sequencer
Quick Start Guide
When applying the controller to a system consisting of fixed speed
compressors with or without unloading capabilities, the controller
requires the user to assign a relay output for each compressor stage
available using the controller’s web pages. (Maximum Stages – 5)
Once the controller setup is completed through the controller’s Mas-
ter View web pages, it is ready to turn the System On, or allow Re-
frigeration, by either clicking the yellow System is Off button on the
Setpoints web page, or using the Manual Menu -> Manual Control
option.
When Fixed Suction Pressure and Fixed Speed Compressors are se-
lected the controller will use the compressor capacity in HP as defined
on the Setpoints Page. Stages will be loaded and unloaded based on
the smallest step available. If all available stages are equal the con-
troller will automatically select the option with the least amount of
runtime.
The Suction Pressure Setpoint will serve as the target pressure the
controller works to achieve while in Refrigeration. The Suction Pres-
sure Differential determines the pressure above and below the Suc-
tion Pressure Setpoint the controller will allow the suction pressure
to vary before it makes an adjustment to the compressor capacity.
Once a stage has been loaded or unloaded that stage must remain on
or off as determined by the Min Comp Runtime and Min Comp Off-
time. Stages of capacity will be made as necessary by the controller,
however, it will not load or unload more often than the time defined
in the Min Compressor Switch Time.
If the system is maintaining the suction pressure within the normal
operating range, which is defined as the Suction Pressure Setpoint
+/- the Suction Pressure Differential it will maintain the current
capacity.
Mode of Control:
Fixed Suction Pressure & Fixed
Speed Compressors
Determining Compressor ON / OFF Order
Mode of Control:
Fixed Suction Pressure with
Digital Scroll Compressors
When applying the controller to a system consisting of fixed speed
compressors with or without unloading capabilities and one digital
scroll, the controller requires the user to assign a relay output for each
compressor stage available using the controller’s web pages.
Once the controller setup has been completed through the control-
ler’s Master View web pages, it is ready to turn the System On, or al-
low Refrigeration, by either clicking the yellow System is Off button
on the Setpoints web page, or using the Manual Menu -> Manual
Control option.
The Digital Scroll will serve as the primary stage to provide the most
consistent suction pressure possible. Initially the compressor will be
started unloaded.
If the pressure rises above the Suction Pressure Setpoint plus the
Suction Pressure Differential the Digital Scroll will be loaded by en-
ergizing the solenoid.
If the pressure falls below the Suction Pressure Setpoint minus the
Suction Pressure Differential it will energize the solenoid to unload
the compressor. If the low pressure is maintained the main digital
scroll’s compressor relay will be de-energized if the Min Comp Run-
time has been met. *
If the Digital Scroll is fully loaded and the pressure exceeds the Suc-
tion Pressure Setpoint plus the Differential the next stage will be
loaded based on the smallest step available. If all available stages are
equal, the controller will automatically select the option with the least
amount of runtime. The compressors will continue to be loaded until
all compressors are running.
If the pressure falls below Suction Pressure Setpoint minus the Suc-
tion Pressure Differential the controller will first unload the Digital
Scroll. The pressure will primarily be controlled by loading and un-
loading the Digital Scroll.
If that is not sufficient to bring the pressure within the normal operat-
ing range, the controller will de-energize the smallest stage, or if all
available stages are equal, the controller will automatically select the
option with the most amount of runtime.
*The Digital Scroll’s requirements for unloading follow its own ruleset
that is not adjustable. It has been designed to be within the limits of the
compressor manufacturer, and to ensure that specification is maintained
the minimum times for transitioning are not adjustable.
