Emerson 2468CD Weather Radio User Manual


 
2468CB & 2468CD Dual Power Supply Version Hydrastep 2468CB and 2468CD Manual
2-26 24685034
Indication Fault(s) Analysis and Corrective Action
State 3 (contd.)
Dirt on electrode
Affected electrode
alternates
between water and
steam.
If the wiring checks carried out as described above have
not located a fault, then dirt on an electrode insulator may
be the cause of the problem giving an effective short-
circuit to ground.
Check all even numbered electrodes alternating between
water and steam for dirt over the external insulator and
clean with a cloth as required.
Checking for dirt on the internal insulator of the electrode
requires draining of the water column (refer to the
appropriate manual for the correct procedure).
Once the water column is drained, check the ac voltage
on each even numbered electrode using a true r.m.s.
voltmeter. Any electrode showing a voltage of less than
3V ac needs cleaning or replacement. Electrodes must
be removed from the column for inspection and cleaning
Note: The electrode insulator can be cleaned using a
clean cloth
Internal circuit fault
on left hand circuit
board or the
display board
If the wiring checks carried out as described above have
not located a fault, then it is possible that an internal fault
exists.
1. Disconnect the electrode cable sockets from the
input boards.
2. Make up four 10-way sockets (six or eight sockets
required for systems with more than 16 points) with
wire links connecting the following pins on each
socket: 1-2, 4-5, 6-7, 9-10.
3. Insert these sockets in place of the electrode cable
sockets in the input boards. The level display should
now show an all steam state and no fault indication.
If this does not occur an internal fault exists.
The circuit fault may be on either input board or the
display board. If spares are available, change the left
hand input board first, and if the fault is not rectified
change the display board followed by the right hand input
board. If spares are not available, call the service
engineer.
State 4
Top half of fault
LED illuminated
No LED pairs
alternating
between water
and steam
Internal circuit fault
on left hand circuit
board or the
display board
This state is indicating a fault which is not related to an
electrode error because no LED pairs are alternating
between water and steam. It is therefore likely that an
internal fault exists.
Follow same procedure as above.
Table 2.3 - Fault analysis/corrective action chart (continued)