Setup Mode Screen 2 – Select The Cycle Type; Thermistor Alarms; Optional Device Alarm; Alarm & Service Mode - Gardner Denver DGH Series Instruction Manual

7. Controller – Level 2
•
Press S to scroll through the choices:
1: -73°C/-100°F
2: -40°C/-40°F
3: -20°C/-4°F
4: +3°C/+38°F
•
When finished, press E to save the selection and move
to Screen 2.
7.8.2 Setup Mode Screen 2 – Select the cycle type.
CYCLE TYPE
DEMAND CYCLE
•
Press S to scroll through the choices: DEMAND
CYCLE, FIXED CYCLE, and MANUAL CYCLE. Note:
DEMAND CYCLE is not available if Class 1 was selected
in the previous screen.
•
When finished, press E to save the selection and move
to Screen 3 (if the dryer has electric drains) or exit Setup
Mode (if the dryer does not have electric drains).
7.8.3 Setup Mode Screen 3 – Test the drains.
TEST DRAIN ?
NO
•
Press S to toggle between NO and YES.
•
Press E to continue.
a. If NO was selected, the controller immediately
exits Setup Mode.
b. If YES was selected, the controller energizes
Drain 1 and Drain 2 for 4 seconds before
exiting Setup Mode.
7.9 Alarm & Service Mode
Alarm & Service Mode is active when the controller is in Display
Mode. It is not active in Program Mode, Setup Mode, or Test
Mode.
NOTE: Alarm messages have priority over Service messages.
Service messages have priority over Display messages. When
an alarm occurs, Display Mode is disabled and only the alarm
message is shown. When a service message is active, it takes
the place of the corresponding service reminder in the Display
Mode (e.g. "HOURS TO SERVICE FILTERS: XXXX" would be
replaced by "SERVICE DRYER FILTERS").
7.9.1 Alarm messages
Alarm messages are displayed on a first-out basis with one
exception. The alarm caused by an open pressure switch at
the end of the regeneration cycle, takes precedence over
existing alarms. See 7.9.1.1 (3).
7.9.1.1 Pressure Switch Alarms
7. Controller – Level 2
There are three alarms for each tower that are triggered by the
tower pressure switches. These alarms can occur in either the
fixed or demand cycle. Following is a brief description of each
alarm.
1. Left or right tower, drying, low pressure
•
Pressure switch open during drying cycle
2. Left or right tower, regenerating, high pressure
•
Pressure switch closed while purge valve is
open (after an initial time delay)
3. Left or right tower, regenerating, low pressure
•
Pressure switch open at the end of the
regenerating cycle

7.9.1.2 Thermistor Alarms

There are two alarms for each of the four thermistors. These
alarms can only occur in the demand cycle. Following is a brief
description of each alarm.
1. Left or right tower, upper or lower sensor, over-
range
•
Temperature above 150°F (66°C)
•
Thermistor circuit shorted
2. Left or right tower, upper or lower sensor, under-
range one cycle
•
Temperature below 40°F (4°C)
•
Thermistor circuit open
7.9.1.3 Optional Device Alarms
1. Electric Drains with Alarm Contacts
•
Each drain has alarm contacts that connect to
the Level 2 Controller.
•
If the contacts open, then a drain alarm is
indicated.
2. Humistat (humidity sensor) - AUX 1 input
•
The humistat has alarm contacts that connect
to the Level 2 controller.
•
If the contacts open, the outlet dew point alarm
is indicated.
3. Dew point sensor - AUX 2 analog input
•
The Level 2 Controller scales the DC analog
input signal to dew point.
•
The user enters an alarm value through the
Level 2 Controller Program Mode.
•
If the measured dew point exceeds the alarm
value, the outlet dew point alarm is indicated.
When an alarm condition occurs, the controller operates as
follows.
•
The alarm LED blinks and the appropriate alarm message
is shown on the text display.
•
The dryer continues to cycle normally (see below for
exception). NOTE: The LEDs for the valves, pressure
switches, and desiccant towers are not used for alarm
indication (as in the Level 1 Controller).
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