5. Commissioning, operation
5.2.1 Limit values for the contact load with resistive load
Maximum rated operating
EN
voltage U
eff
Rated operating current
Switch-on current
Switch-off current
Continuous current
Maximum switching power
Do not exceed the limit values. In order to permanently ensure safe operation, the
following load values are recommended:
Voltage
(per IEC 38)
DC/AC
230 V
110 V
48 V
24 V
The switching current must not be less than 20 mA with low voltages for switching relia-
bility reasons.
Overcurrent protectors
The instruments do not provide for incorporated overcurrent protectors. Should protec-
tors be required, the following values in accordance with EN 60947-5-1 are to be
recommended.
Voltage 24 V: 2 A
■
Voltage 250 V: 1 A
■
5.2.2 Contact protection measures
Mechanical contacts must not exceed the specified electrical values for switching
current, switching voltage and switching power independent of each other, not even for
a short time only.
14
Gas-filled instruments
AC 250 V
1 A
1 A
0.6 A
30 W, 50 VA
Gas-filled instruments
Resistive load
DC
AC
100 mA
120 mA
200 mA
240 mA
300 mA
450 mA
400 mA
600 mA
For higher loads, and for instruments with liquid-filled cases,
WIKA model 905.1X contact protection relays are recommended.
WIKA operating instructions gas density monitor model GDM-100
Liquid-filled instruments
Inductive load
Resistive load
cos ϕ >0.7
DC
65 mA
65 mA
130 mA
130 mA
200 mA
190 mA
250 mA
250 mA
Liquid-filled instruments
AC 250 V
1 A
1 A
0.6 A
20 W, 20 VA
Inductive load
AC
cos ϕ >0.7
90 mA
40 mA
180 mA
85 mA
330 mA
130 mA
450 mA
150 mA