Operation
MRH 06.04.2017
13
9.3
Dual use of hatch + fan (daily powered venti emergency use)
In addition to serially equipped device it is necessary to provide following safety measures:
Protective guard to completely prevent access to opened/closed hatch cover – it is to provide by installer up to
roof design.
Hazard signs.
Once safety assured with above measures, it is to observe:
Safety components must not be bypassed or put out of function.
Prevent sucking of foreign particles, this can destroy the fan.
Switching frequency:
-
the fan is intended for S1 continuous operation!
-
the control equipment must not allow any extreme switching!
The fan may operate only within the limits declared on the nameplate.
In case of fire, bridging of motor protective devices is necessary to assure operation. Switch on max. speed even
after eventual short supply cut off must be assured.
If frequency converter is used for normal ventilation, it must be bridged in case of fire – see also instruction of
the fan.
In case of speed control via frequency converter - min. 20 Hz ÷ max. 50 Hz (rsp. 60 Hz, if declared for 60 Hz), make
sure that the voltage peaks on the connection terminals of the fan are lower than allowed in the fan`s instruction.
ATTENTION
Hazard with risk of additional costs
Check provisions for speed control in the instruction of the fan (usually it is recommended a combina-
tion of frequency converter and appropriate all-pole sinus filter or minimum dU/dt filter).
At frequency controlled units additional EMC protection of cable and service switch could be needed
(on request).
Subsequently fitting of EMC shielded cable from motor to connection box/service switch is connected
with disassembly of the fan!
The motors cannot be voltage-controlled! The motor can overheat due to increased current at lower
voltage.
9.4
Dual use of hatch + fan (daily natural venti emergency use)
In addition to serially equipped device it is necessary to provide following safety measures:
Protective guard to completely prevent access to opened/closed hatch cover – it is to provide by installer up to
roof design.
Hazard signs
Once safety assured with above measures, it is to observe:
Safety components must not be bypassed or put out of function.
Prevent sucking of foreign particles, this can destroy the fan.
Switching frequency of hatch must be in accordance with the actuator`s instructions, especially intermittence and
time of presence of control voltage (see also Appendix 4).
Weather protection devices should be applied to limit use (rain, strong wind).
The fan may operate only within the limits declared on the nameplate.
In case of fire, bridging of motor protective devices is necessary to assure operation. Switch on max. speed even
after eventual short supply cut off must be assured.
