16
3916010 06.16
Fig. 16
6. MAINTENANCE AND TROUBLESHOOTING
6.1 TROUBLESHOOTING
Observation
Problem
Solution
No light in the SUPPLY diode
(Fig 16-A)
Blown fuse or interrupted power supply
1) Check the fuse (Fig. 16-B) and the fan power.
2) Check the power supply.
Constant light in “Increasing Speed”
diode (Fig 16-E)
System fault
1) Check that the probe is connected to the “-” port on the XTP
transducer.
2) Check that the probe is not clogged.
CAUTION: Do not blow into the XTP transducer.
3) Check that the fan is running.
4) Set-point is too high for the fan capacity. Check/reduce
setting.
5) Check the entire system’s adjustment, including any
balancing baffles installed.
6) Check duct for leakages.
7) Check the power supply to the XTP..
Constant light in “Decreasing
Speed” diode (Fig 16-D)
System fault
1) The natural stack effect prevents the system from reaching
the set-point. Check the adjustment. If necessary, install a
balancing baffle or other resistance in the duct.
2) The probe may be in a bad location..
Constant light in ALARM diode (Fig.
16-H)
, but no light in FAN diode (Fig.
16-G) (Can only occur when MANUAL
RESET is ON (Fig. 16-F)
Power outage
Press the RESET button (Fig. 16-C) for (1) second — see
warning.
Constant light in Alarm diode
and light in fan diode (Fig. 16-H)
Insufficient pressure
1) Press the RESET button (Fig. 16-C) — see warning.
2) Check that the service disconnect switch is working properly.
3) Check the connectors, chimney and fan for blocking
restrictions.
Flashing ALARM diode (Fig. 16-H)
Can only occur when PDS CHECK is ON
(Fig. 16-F)
Error in safety system (PDS)
1) Check that a PDS is installed.
2) Check the setting of the safety system (the natural stack
effect can prevent close/alternatively the PDS CHECK dipswitch
can be moved to its OFF position.
3) Check the connection to the PDS and the PDS itself.
The MEC 18 does not regulate and
the fan is running at full speed
The neutral connection is shared with
other devices.
1) Check the amp-draw on terminal Nreg. If it is “0”, the neutral
connection to the fan is being shared.
Some appliances require a certain
startup procedure after a shutdown.
Follow this procedure prior to pressing
the RESET button (Fig. 16-C).
!
MEC 18
E X H A U S T C O N T R O L
Summary of Contents for MEC 18
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