Controllers – General; Desiccant Dryer Controllers - Gardner Denver DGH Series Instruction Manual

5. Controllers – General
5. Controllers – General
5.1 Overview
Solid-state dryer controls are located in a polycarbonate, NEMA
Class 4/4X, IP66 rated electrical enclosure mounted to a center
panel located between the two desiccant towers. Controls are
available in two functional levels. Both controls offer four fixed-
time cycles that provide dew points corresponding to ISO
compressed air quality classes 1 through 4. A key difference
between the two controls is the way in which they address
energy savings. When inlet flow is less than the adjusted rated
capacity of the dryer, average purge air requirements are
Category
General
Operating Modes
(See Note 5)
Digital I/O
Analog I/O
(12 bit accuracy)
Communication
5. Controllers – General

Desiccant Dryer Controllers

Feature
AC Input voltage: 85-264 VAC, 47-63 Hz (See Note 1)
DC Input voltage: 11.5- 28 VDC (See Note 1)
Auxiliary power terminals (See Note 2)
Solenoid valve coil voltage
NEMA 4/4X, IP 66 electrical enclosure rating
Soft on/off switch with two power recovery modes (See Note 3)
Tower status LEDs (green=drying, amber=regenerating)
Process valve status LEDs (on = valve open, off = valve closed)
Operating mode LEDs (see next category for number of modes)
Alarm LED (red)
Voltage-free alarm contacts, 5A rating
Alarm reset switch (mounted on front panel)
Service reminder LEDs (See Note 4)
Vacuum fluorescent text display
60-150 or 120-250 psig MOP (selectable via jumper on circuit board)
ISO Class 1 (-100°F/-73°C PDPT) – fixed cycle (4 minute)
ISO Class 2 (-40°F/-40°C PDPT) – fixed cycle (10 minute)
ISO Class 3 (-4°F/-20°C PDPT) – fixed cycle (16 minute)
ISO Class 4 (+38°F/+3°C PDPT) – fixed cycle (24 minute)
Fixed cycle Energy (purge) Saver (See Note 6)
Manual cycle (test mode)
ISO Class 2 (-40°F/-40°C PDPT) – demand cycle
ISO Class 3 (-4°F/-20°C PDPT) – demand cycle
ISO Class 4 (+38°F/+3°C PDPT) – demand cycle
Controlled shutdown and restart (upon user supplied contact closure)
Tower pressure switches (2)
High humidity or dew point alarm
Filter monitor alarm (1 or 2 filters)
Electric drain alarm (1 or 2 filters)
Electric drain test (1 or 2 filters)
Thermistors (4)
Analog input #1 (0-5 VDC) Dew point transmitter
Analog input #2 (0-5 VDC) Pressure transducer
Analog input #3 (0-5 VDC) Temperature sensor
RS232 communication port
Table 5-1 (continued on next page)
Feature Comparison – Level 1 and 2 Controllers
reduced. This reduction can translate to energy savings at the air
compressor.
The Level 1 Controller offers 8 selectable fixed-cycle Energy
(purge) Saver modes (0% to 70% in 10 % increments) to reduce
purge time to match the load on the dryer.
Level 2 Controllers feature the Automatic Purge Saving System
(APSS) as described in Sections 3.2 and 3.4. When Level 2
Controllers are operated in demand rather than fixed cycle
modes, the APSS automatically adjusts to dryer loading and
extends drying time when possible. Average purge use is thus
automatically reduced.
A feature-by-feature comparison of Level 1 and 2 Controllers can
be found in Table 5-1.
- 14 –
Level 2
Level 1
Fixed Cycle
Fixed Cycle Only
and APSS
12 VDC 12 VDC
Optional
Optional
Optional
Optional
Optional
Optional
Optional