Emerson 2468CB, 2468CD manual 3c-10

Opto-isolated Output Board Option Hydrastep 2468CB & 2468CD Manual

3c.3.2.3 ‘One out of Two’ Opto-output Alarm System

Either of the opto-outputs involved can signal an alarm when their assigned electrode detects a water/steam interface change. The alarm condition is selected by switch SW5 to provide an opto-output in conducting mode in water W or in a conducting mode in steam S.

Case A - Opto-output circuit normally open circuit, short circuit either one to trip

To alarm annunciator or

tripping device

TR2	1	PL 2	+ VE	- VE	PL 2	1
	2					2
	3					3
Opto-output 1	4					4

Odd Electrodes	Note:	External power must
(RH Input Board)
		be applied as shown.
		See specification for
		power requirements

TR2

Opto-output 1

Even Electrodes (LH Input Board)

(Switch SW5 is set to S for low level alarms and set to W for high level alarms)

Case B - Opto-output circuit normally short circuit, open circuit either one to trip

			To alarm annunciator or
			tripping device
TR2	1	PL 2	+ VE - VE	PL 2
	2
	3
Opto-output 1	4

Odd Electrodes	Note:	External power must
(RH Input Board)
		be applied as shown.
		See specification for
		power requirements

1

2

3

4

TR2

Opto-output 1

Even Electrodes (LH Input Board)

(Switch SW5 is set to W for low level alarms and set to S for high level alarms)

3c-10 24685034