Emerson 2468CB, 2468CD manual 3b-12

Delay Relay Output Board Option Hydrastep 2468CB and 2468CD Manual

3b.3.2.3 ‘One out of Two’ Relay Alarm System

Either of the relays involved can cause an alarm when their assigned electrode registers an alarm condition. The alarm condition is selected by switch SW5 to provide relay energisation in water EW or energisation in steam ES.

Case A - Relays normally energised, de-energise either one to trip

		(Relays shown in de-energised state)
RL 1	1	PL 2	PL 2	1	RL 1
	2		To alarm annunciator	2
	3			3
	4			4
Odd electrodes					Even electrodes
(RH input board)		Alarm off when contacts closed			(LH input board)
RL 1	1	PL 2	PL 2	1	RL 1
	2			2
	3			3
	4		To alarm annunciator	4
Odd electrodes					Even electrodes
(RH input board)		Alarm off when contacts open			(LH input board)
	(Switch SW5 is set to ES for low level alarms and set to EW for high level alarms)

Case B - Relays normally de-energised, energise either one to trip

		(Relays shown in de-energised state)
RL 1	1	PL 2		PL 2	1	RL 1
	2				2
	3		To alarm annunciator		3
	4				4
Odd electrodes						Even electrodes
(RH input board)		Alarm off when contacts closed				(LH input board)
RL 1	1	PL 2	To alarm annunciator	PL 2	1	RL 1
	2				2
	3				3
	4				4
Odd electrodes						Even electrodes
(RH input board)		Alarm off when contacts open				(LH input board)
	(Switch SW5 is set to ES for low level alarms and set to EW for high level alarms)

3b-12 24685034