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7.3 Safety interlock
Risk of electrical shock!
Hazardous electrical voltage.
When standard wiring was made, terminal 1
shows 230 VAC after commisioning.
Across terminal 1 and 2 the so-called safety
interlock is wired. This wiring allows for inte-
gration of safety devices. In case of an open
safety interlock the steam humidifier does not
operate.
Factory setting leaves the safety interlock
open!
Install contact interlocks, e.g. a max. hygro-
stat, vane relays, pressure controllers, air
interlock devices etc. in series across termi-
nal 1 and 2.
Contacts across terminals 1 and 2 must
be potential free and properly rated!
Rating must comply with the control voltage
in use.
Best practice implies the integration of a max.
hygrostat in the safety interlock wiring to pro-
tect against over-humidification due to a r.h.
sensor malfunction.
7.4 Control signal
As described in the „Unit Control“ chapter,
section „Provider level submenue and its
parameters“, the unit control type is deter-
mined by parameter „1-2“, „control signal“. In
accordance with the control type selected,
terminal wiring of the connection terminal (s.
„Unit control“ chapter, section „Main PCB
connections“ is to be made.
7.4.1 1-step operation
Steam humidifier operation is controlled by
the contact across terminals 3 and 5 provided
by the customer. This contact needs only to
be low voltage proof.
7.4.2 Operation with an active humi-
dity sensor or external control-
ler
When driving the steam humidifier by an
active r.h. sensor or external controller (e.g. a
PLC), control signals in the range of 0...10 V,
0...20 mA or 0...140 Ohm may be applied.
Each one of the signal types is connected to
a dedicated terminal (see „Unit control“
chapter, section „Main PCB connections“).
Reference is always to terminal 4, GND.
:$51,1*
Safety interlock terminals
1/2 on main PCB
3OHDVHQRWH
127,&(
127,&(
3
45
6
7
20 VDC
Customer-provided contact
for 1-step operation
3
4
5
6
7
20 VDC
GND
0...10V
0...20mA
Terminals for
control signals
0...140 Ohm