55
HumiTherm Ultra
User Manual
APPENDIX - D
STANDBY CONTROL GADGETS
If the Controller is supplied with Standby Control Gadgets option, 5 additional digital outputs are provided for interfacing an
additional set of Control Gadgets as standby. That is, there are two sets of Control Gadgets; Main & Standby.
The additional 5 outputs (besides 3 standard outputs, viz., Main Compressor, Main Heater & Main Humidifier) are; Standby
Compressor, Standby Heater, Standby Humidifier, Main Set Select & Standby Set Select. The Main Set Select & the Standby
Set Select outputs are used to drive two external gadgets (usually electromechanical relays) that switch power to SSRs that
drive Main & Standby gadgets respectively. Refer generic electrical connection diagram below.
NO
C
NC
+12 V Coil
NO
C
NC
+12 V Coil
Stby
Set Select
Heater
Humidifier
Compressor
Alarm
Main Set Select
Heater
Humidifier
Compressor
Main
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
24
Door Lock
Standby
Digital Outputs
+
-
+
-
+
-
+
-
+
-
+
-
+
-
+
-
+
-
+
-
Line
Neutral
Contactor
SSR
NO
C
NC
+12 V Coil
Relay
Control Gadget Fail Detection
The term control gadget failure applies to the complete set (Main or Standby) rather than an individual gadget. The failure may
arise due to reasons like heater-break, compressor tripping / failure, SSR output short circuiting, etc. The failure of any gadget
is treated as a set failure and the entire set is switched to the working set.
