1 - 6
The thermal overload switch turns off the compressor in
the event of high motor temperature. This switch is not ac-
cessible. It will automatically reset when the motor has
cooled to an acceptable level. Refer to the Field Service
Guide for causes of and remedies for compressor motor
overheating.
ENERGY MANAGEMENT
CONTROLLER (EMC)
The EMC (see Figure 3) is a multi-function controller de-
signed to provide:
• Power-off timer (counts # of seconds dryer is without
power)
• Pressure switch monitor
• Warm-up delay on compressor activation after loss of
power
• Auto restart
• Compressor control logic
• Dew point control
• Alarm indicators
• Automatic drain valve timer
• Temperature monitoring
• Temperature display in Fahrenheit or Celsius
• Keypad functions
• Non-volatile memory
• Cumulative run-time/compressor-on-time recording
• Cumulative time reset function
Controller Operation
On power up, the controller will perform a lamp test that
will light each LED on the display.
The controller then checks to see if the high pressure switch
is closed—indicating a normal condition.
• If the pressure switch is open (no line voltage detected),
the dryer will activate the alarm relay and display “HiP.”
This condition will remain until the high pressure switch
is manually reset (see High Pressure HiP Alarm sec-
tion on page 1-10).
• If the pressure switch is closed, the dryer then checks
to see how long power has been removed. A battery
operated timer maintains a count of the time the dryer
has been without power.
While operating, the dryer will compute temperatures and
monitor alarm conditions.
Dryer Warmup
During the initial installation, if power is disconnected or if
a power loss occurs, the dryer will shutdown for a specified
delay time (see table below) so that the crankcase heater
has sufficient time to warm up before starting.
Warmup Delay Times
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The display will show the minutes remaining in the warmup period.
Power off for more than 1 hour:
Once power is restored, the display will show the number
of minutes remaining in the warmup period and the Power
On LED will light. If the START button is pressed during
the warmup period, the Dryer On LED will blink, indicating
that the dryer will resume normal operation after the delay
timer has expired.
If the dryer was running when the power loss occurred,
then the Auto Restart LED will blink. After the delay, the
Auto Restart LED will stop blinking and the Dryer On LED
will light, indicating the dryer has resumed normal opera-
tion.
If the dryer was off when the power loss occurred, follow
the Startup procedure on page 1-10 to start the dryer.
Power off for less than 1 hour:
Once power is restored, the Power On LED will light, the
display will show the process control temperature, and the
Process Control Temperature LED will light. Either the Fahr-
enheit or Celsius LED lights (depending on which mode
was selected).
If the dryer was on when the power loss occurred, then the
Auto Restart LED and the Dryer On LED will light, and the
auto drain cycle will start. The Auto Restart LED will remain
on until the STOP button is pressed.
If the dryer was off when the power loss occurred, then
only the LEDs for Power On, Process Control Tempera-
ture, and either Fahrenheit or Celsius will light; and the dis-
play will show the process control temperature.
