H-25C Instruction Manual
Instruction 3015-0216
17
2.2.4 Setting the “RELAY” (Relay State Selector) Switch
Note: The “RELAY” switch (3) must be set if the instrument is equipped with the alarm contact signal
output function.
The alarm contact signal is output when the leak flow is greater than or equal to the alarm setting.
The “RELAY” switch selects whether the relay is to be energized or de-energized at the time.
Since the relay contact is set up at the factory as a normally open (N)) contact, selecting “energize”
will result in the contacts closing when the signal is output, whereas selecting “de-energize” will result
in the contacts opening.
It is also possible to change the relay connections to use the normally closed (NC) contact (by
changing the position of jumper JP1 on the printed circuit board inside the unit).
If you change to the NC contact, then the contacts will be in the closed state when power is OFF. If
you have changed to the NC contact, then to have the contacts go to the closed state at time of alarm
you must set the switch lever to the “de-energize” position.
