Maintenance switch

The purpose of the main switch input is to allow a controlled shut-down and restart procedure of the outputs. Typically, contacts from a local isolator next to the fan motor will be used. When the local isolator is switched off, the input MaintSw will be 0 and the outputs "Stage1Cmd" and "Stage2Cmd" will be switched off without delay. When the maintenance switch becomes 1 again, the plant can be restarted.

The maintenance switch will generate a alarm at the "OffAlarm" output.

With the parameter ALM-01 the user can change the contact type of the maint. switch to NO (normally open) or NC (normally closed).


Description

Default value

ALM-01: maint switch NO/ NC; 1 = NC

1

ALM-02: maint switch reset type

0 = manual reset

1 = auto reset

1


Manual- or automatic reset

After switching back the maintenance switch, a reset is required.

The user can with parameter ALM-02 choose between manual or automatic reset.

In case of manual reset, the user has to connect the Reset input of the macro to the reset button.