SKG4-E Gas Fired Humidifier
Installation Instructions and User Manual
Page | - 41 -
Stage 9 - Electrical Control Connections
Electrical Control Connections
The SKG4 humidifier has a modulating control system and requires an analog control signal.
All controls connections have been grouped on a specific control board.
Control
Board
JP3
NETWORK
BOARD
NETWORK
PCB
JP4
T
B
4
T
B
3
T
B
2
T
B
5
T
B
6
Airflow switch
High limit humidistat
Interlock
On/Off demand contact
Alarm Contacts
Service Contacts
Control Demand
Room Humidity
Duct Humidity
Steam Output
Common
24 Vac
A+
B-
RS 485
(BACnet MS/TP
or Modbus RTU)
24 Vac
T
B
1
A+
B-
RS 485
(HRL24)
Common
Normally Open
Normally Closed
Common
Normally Open
Normally Closed
1
2
1
2
1
2
3
4
5
1
2
3
4
5
6
1
2
3
1
2
3
Power Output
Analog Inputs
Analog Output
Safety Contacts
T
B
7
Network Contacts
Water Leak
Detection
1
2
Illustration 39 - Electrical Control Connections
Safety Contact Connections
The
Airflow switch
contact must be wired between terminals TB3 1&2. If this contact opens,
operation of the SKG4 unit will stop. The unit will display the airflow switch as open, but will not
generate an alarm. If an airflow switch is not used, install a jumper between terminals TB3 1&2.
The
High limit humidistat
contact must be wired between terminals TB3 1&3. If this contact opens,
operation of the SKG4 unit will stop and an
alarm
message will be displayed. If a high limit humidistat
is not used, install a jumper between terminals TB3 1&3.
The
Interlock
must be wired between terminals TB3 1&4. If this contact opens, operation of the SKG4
unit will stop. The unit will display the Interlock as open, but will not generate an alarm. If Interlock is
not used, install a jumper between terminals TB3 1&4.
Dry Contacts
Two series of volt free contacts are provided:
1. Alarm Contacts
2. Service Contacts
These contacts are used to switch a low voltage, ideally 24V, with a switching current of no
more than 3 Amps.
Each series has one Normally Closed contact and one Normally Open contact.
It is recommended to use the Normally Closed contact, as this contact will open in the event
of a humidifier fault.
Summary of Contents for SKG4-E Series
Page 70: ...Notes ...
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