Emerson 2468CB, 2468CD 2-24, Indication, Faults, Analysis and Corrective Action, State 1 contd

2468CB & 2468CD Dual Power Supply Version Hydrastep 2468CB and 2468CD Manual

Indication	Fault(s)	Analysis and Corrective Action
State 1 (contd.)	Incorrect wiring,	Check ac voltage on electrodes with a true r.m.s.
	broken connection	voltmeter. A voltage of less than 0.1V ac indicates a fault
	or damaged cable	condition.
	assembly	If wiring to the electrode is correct and the electrode
	Affected	gives a voltage reading of greater than 0.1V ac and a
	electrode(s)	fault is still indicated, carry out the following procedure:
	alternate between	1. Remove both conductors from the suspect electrode.
	water and steam.	With the conductors isolated from each other, the
		level display should show the electrode as
		alternating between water and steam (green and
		red).
		2. With the conductors touching each other, the level
		display should show electrode as being in steam.
		The above procedure checks the electrode wiring. If the
		display does not show the correct results, then check for
		a break in either of the suspect electrode conductors.
		Carry out repair to any faulty connection or substitute a
		new conductor or cable assembly in place of the
		defective item.
	Dirt on electrode	If the wiring checks carried out as described above have
	Affected	not located a fault, then dirt on an electrode insulator may
		be the cause of the problem giving an effective short-
	electrode(s)
		circuit to ground.
	alternate between
		Check the electrodes for dirt over the external insulator
	water and steam.
		and clean with a cloth as required.
		Checking for dirt on the internal insulator of the electrode
		requires the draining of the water column (refer to Part 2
		of this manual for the correct procedure).
		Once the water column is drained, check the ac voltage
		on each 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 fault	If the wiring checks carried out as described above have
		not located a fault, then it is possible an internal fault
		exists.
		1. Disconnect the electrode cable sockets from the
		input board.
		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.

Table 2.3 - Fault analysis/corrective action chart (continued)

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