Pneumatech AD Series, Owner'S Manual

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DIGITAL DRY GUARD™ (DDG)
CONTROLLER OPERATION
(Available on some models as standard, and others as
an option.)
The DDG Controller is capable of 4-channel temperature
display, drain control, and service due and alarm
indication.
Temperature Display
The DDG controller is capable of 4-channel temperature
display. The unit displays refrigerant suction temperature
(measured immediately downstream from the refrigerant/
air heat exchanger), incoming air temperature, ambient
air temperature (or incoming water temperature for units
with a water-cooled condenser), and dew point
temperature (optional). Only one temperature can be
displayed on the LCD screen at a time. In the normal
operational mode, pushing the UP (
↑ ) or DOWN ( ↓ )
arrow keys will cycle the temperature displayed, while
LEDs on the DDG unit indicate which temperature is
being displayed. Pushing the SELECT key will cycle
between Fahrenheit and Celsius temperature scales.
The LED labeled “OPTIONAL” corresponds to the dew
point temperature. If your unit does not include this
option, the temperature displayed when the “OPTIONAL”
LED is lit will be about 30°F (-1°C) by default. This does
NOT indicate that the dew point is actually 30°F (-1°C).
Drain Operation
Locking/Unlocking Drain Time Settings:
The ON
TIME and OFF TIME settings for all modes of drain
operation can be unlocked or locked to avoid inadvertent
changes to these settings. In the unlocked condition, the
time settings will flash after the SELECT key is pressed
momentarily, indicating that the values can be changed
by pressing the UP (
↑ ) or DOWN ( ↓ ) arrow keys. In the
locked condition, the SELECT key must be held down
for 5 seconds before the display will flash and the
settings can be changed. With the display flashing,
pushing the SELECT key momentarily will return to
normal unlocked operation and holding the SELECT key
down for 5 seconds will return to normal locked
operation.
Setting Drain ON TIME and OFF TIME:
1. Press the UP ( ↑ ) or DOWN ( ↓ ) arrow keys until the
LED indicates that ON TIME or OFF TIME has been
selected.
2. Press SELECT momentarily (if unlocked) or hold
until the display starts flashing (if locked). If you do
not know whether the setting is locked or not, simply
press the select button momentarily. If the digits on
the LCD display do not start flashing, the setting is
locked.
3. Press UP (
↑ ) or DOWN ( ↓ ) arrow keys to change the
settings. The ON TIME is indicated in seconds and
changes in 0.5-second increments in a range of 0 to
60 seconds. The OFF TIME is indicated in minutes
and changes in 0.5-minute increments in a range of
0 to 60 minutes.
Modes of Drain Operation:
The DDG Controller has
two modes of drain operation for different drain types.
The
mode of operation for timed drains (i.e. 4477 A, B,
or C models) is described below as item “A.” The mode
of operation for fully automatic float operated drains (i.e.
model 4488) is described as item “B.” For all modes, the
“DRAINS POWER ON” LED indicates that the drain is
receiving power. Pushing the DRAIN TEST key will send
power to the drain if it is not already receiving power.
A. Timed Drain Mode (model 4477 A, B, or C drains):
Set ON TIME and OFF TIME to non-zero values.
Settings should be such that fluid is adequately
drained without allowing excessive air loss.
B. Demand Drain Mode (model 4488 drains): Set ON
TIME and OFF TIME to zero. Drain is given
continuous power supply and will operate normally.
In this mode, pushing the DRAIN TEST button will
have no effect.
Alarm Indication
The following conditions can cause the alarm indicator to
light:
• Compressor overload
• Low refrigerant suction pressure
• High refrigerant discharge pressure
• Low oil pressure (semi-hermetic compressors only)
A qualified refrigeration mechanic should identify and
correct the problem if an alarm condition occurs.
In most
cases it will be necessary to firmly depress the reset
push-button located on the dual-pressure switch,
which is inside the electrical enclosure.
Follow all
safety procedures applicable to electrical equipment
when opening the electrical enclosure.
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