Troubleshooting
4.4 Functional check of the cooling system
To test the function of the cooling system you can use the following functions tables.
During program course use a multimeter to measure the output signal at the analog output AA1 (pins 17 and
18) of the controller MB1 I/O-board (-3N2).
The clocking of the corresponding valves can be detected by the corresponding LED.
The values given under X indicate the start values. The values given under W indicate the target values to be
triggered. The target values must not be reached for the test, it is sufficient to watch them during the first five
minutes.
Humidity switch (-8S1) ON
Temperature / Humidity
Solenoid valve
(-7Y1 ),
Binary output BA2
on controller MB1
I/O-board,
Solenoid valve
(-7Y2 ),
Binary output BA3
on controller MB1
I/O-board,
Analog output AA1 on
controller MB1 I/O-
board, controller cooling
X: Temperature: 20°C to 25°C
68°F to 75°F
Humidity: < 95 % r.H.
W: Temperature: 10°C / 50°F
Clocking
on / off
2 / 15
seconds
Clocking
on / off
2 / 15
seconds
According to regulation
ratio of temperature
initially ≤ 5 V DC
gradually decreasing
X:
Temperature: 20°C to 25°C
68°F to 75°F
Humidity: 50 % r.H.
W: Temperature: 10°C / 50°F
Humidity: 0 % r.H.
1 minute
on / off
2 / 15
seconds
Clocking
on / off
2 / 15
seconds
ratio of temperature and
humidity
initially ≤ 5 V DC
gradually decreasing
X: Temper
68°F to 122°F
Humidity: < 50 % r.H.
W: Temperature: 50°C / 122°F
Humidity: 95 % r.H.
“OFF”
Clocking
on / off
2 / 15
seconds
near 0 V
See also chap. 10.5, “checking the step motor valve”.
Service Manual KBF (E5.2) 04-2015 25