Emerson 2468CB, 2468CD manual 3b-14

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

3b.3.2.5 ‘Two out of Four’ Relay Alarm System

In the following diagrams (5A & 5B)  indicate the electrode channel selected for each relay. A fully functioning system (NO FAULTS) will perform a low level trip at electrode level 3. For a high level trip, using electrode channels 11, 12, 9 and 10 respectively and switch SW5 set for ES, a healthy system would trip at level 10.

Case A - Relays normally energised, de-energise one in each pair to trip

(Relays shown in de-energised state)

RL 1

3

RL 2

1

Odd electrodes (RH input board)

PL 2

1

2

3

4

5

6

7

8

RL 1

4

RL 2

2

Even electrodes (LH input board)

1	PL 2
2
3
4	To alarm
	annunciator
5	or tripping
	device

6

7

8

Alarm off when contacts open

(Switch SW5 is set to EW for low-level alarms and set to ES for high-level alarms)

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

	(Relays shown in de-energised state)
RL 1	PL 2	RL 1	PL 2
	1		1
	2		2
3	3	4	3
	4		4
	5		5
RL 2	6	RL 2	6
1	7	2	7
	8		8
Odd electrodes		Even electrodes
(RH input board)		(LH input board)

Alarm off when contacts open

(Switch SW5 is set to EW for low-level alarms and set to ES for high-level alarms)

To alarm

annunciator

or tripping

device

3b-14 24685034