Emerson 2468CD, 2468CB manual 2-25, Indication

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

Indication	Fault(s)	Analysis and Corrective Action
State 1 (contd.)		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 input
		board first and if the fault is not rectified change the
		display board. If spares are not available, call the
		service engineer.
State 2	Internal fault	This state is indicating a fault which is not related to an
Top and bottom		electrode error because no LED pairs are alternating
		between water and steam. It is therefore likely that an
halves of fault
		internal fault exists.
LED illuminated
		Follow same procedure as above.
No LED pairs
alternating
between water
and steam
State 3	Electrode wiring or	Check that all even numbered electrodes indicating
Top half of fault	internal fault	water have the correct pair of conductors connected.
		Check the connections to the left hand input board.
LED illuminated	Even numbered
		Rectify wiring if incorrect.
One or more	electrode connection
		Check ac voltage on all even electrodes immersed in
	open-circuit or
LED pairs
	short-circuit to earth	water with a true r.m.s. voltmeter. A voltage of less than
alternating
		0.1V ac indicates a fault condition.
between water	Affected electrode
		If wiring to all even electrodes is correct and the
and steam	alternates between
	water and steam.	electrodes still give a voltage reading of greater than
	Incorrect wiring,	0.1V ac and a fault is still indicated, carry out the
		following procedure:
	broken connection or
	damaged cable	1. Remove both conductors from electrode 2. With the
	assembly	conductors isolated from each other, the level
		display should show electrode 2 as alternating
		between water and steam (green and red).
		2. With the conductors touching each other, the level
		display should show electrode 2 as being in steam.
		3. Repeat operations 1 and 2 for all affected even
		numbered electrodes until a faulty indication is
		found.
		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.

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

24685034 2-25