IMO MRH

34 MRH 18.08.2022

**** Circuit diagram: drawn position “CLOSED” (Potential free NC contacts, load capacity 24VDC/1A)

Connection of actuator`s internal floating limit switches in the control box (1 actuator up to MRH 1000)

9-10 opened, 10-11 closed in closed hatch position

9-10 closed, 10-11 opened in opened hatch position

9-10 closed, 10-11 closed in any intermediary position of the hatch cover

***** Instruction regarding actuator 2 is relevant for MRH 1120 and MRH 1250 only

Connection of actuator`s internal floating limit switches in the

control box (2 actuators at MRH 1120, 1250)

9-10, 12-13 opened, 10-11, 13-14 closed in closed hatch position

9-10, 12-13 closed, 10-11, 13-14 opened in opened hatch position

9-10, 12-13 closed, 10-11, 13-14 closed in any intermediary position of the hatch co-

ver

Emergency (Fire) mode recommendations for MRH:

6. Bypass non-vital protection and security devices.

7. Switch on L1 (power on L1 with 230V) for hatch opening of MRH. If service switch is in recommended ready

state in position 1  hatch is opening.

8. Wait for 20s. The recommended start of the fan is 20 s after starting actuator for cover opening, to ensure

vertical exhaust of hot gases.

9. Start axial fan.

10. Switch off L1 (power off L1) when hatch is fully opened (check limit switch 9-10, 12-13 closed, 10-11, 13-14

opened in opened hatch position).

Power supply MRH 400÷1000 (1120÷1250) 230VAC consists of:

MRH 400÷1000

MRH 1120, 1250

3. Control box with service switch 230V for MRH hatch actuator

1 pcs.

4. Power supply 230VAC



24VDC

1 pcs. 230VAC 

24VDC, 8A

2 pcs. 230VAC 

24VDC, 8A (2x8=16A)

MRH 400÷1000

MRH 1120, 1250

Recommended fuses, slow blow type

2,5A

Power supply

1 or 2 Pcs

Control box with

service switch

Shown example for

MRH 400-1000