58
Zehnder Eversky
21.7. List and meaning of alarms
No.
Display
Class
Time
Threshold
Action
Conditions
Causes
(There may be several causes)
1
VAS fault
A
30s
Set value for LIFO
pressure switch
Unit stopped
The contact of the
runback pressure switch
of the supply fan has
remained open for more
than 30s during normal
operation of the fan unit.
The UDI2 input must be
in closed state "Fer"
when the ventilation unit
is in operation, in the
open state "Ouv" when
the unit is off.
The pressure switch is of
type NO (normally open).
Fan motor for supply (blowing)°:
- Faulty
- Control signal 0-10 V inverted
- Faulty electrical wiring/connection
Fan control pressure switch:
- Faulty
- Poor electrical connection
- Poor air connection
- Incorrect setting (nominal factory
setting = 25 Pa)
- Faulty electrical wiring/connection
Transparent tubes for the fan control
pressure switch:
- Poor connection
- Presence of internal condensation
water. This may be due to a prolonged
shut-down of the unit, or repeated/too
many Start/Stop cycles. Set the
machine for continuous operation.
- Foreign matter or dust in the tube or
pressure tap.
The low speed and/or normal speed
setpoint is too low, and the fan speed
signal does not reach sufficient
pressure to switch on the fan control
pressure switch.
Motorised supply air damper RMS
remains in closed position. Clogged
ductwork.
