Vaisala DD-23 User Manual

IM-EN-DD23-C

Instruction Manual

Digital Divert Control System

DD-23

PUBLISHED BY

Vaisala Oyj

Vanha Nurmijärventie 21, FI-01670 Vantaa, Finland

P.O. Box 26, FI-00421 Helsinki, Finland

[phone]

Visit our Internet pages at www.vaisala.com.

© Vaisala 2021

WARNING

The process medium may be hot or otherwise hazardous. Precautions when removing the sensor from the process line:

Makesurethattheprocesslineisnotunderpressure. Openaventvalvetotheatmosphere. Fora retractor/isolationvalvethelinepressureshouldbewithinspecifications.

Foraprismwashsystem,closeahandvalveforthewashmediumanddisablethewashvalve. Loosen theclamporflangeboltscautiously,bepreparedtotightenagain. Beoutofthewayofanypossible splashandensurethepossibilityofescape.

Useshieldsandprotectiveclothingadequatefortheprocessmedium. Donotrelyonavoidanceof contactwiththeprocessmedium.

Itistheuser’sresponsibilitytofollowmanufacturer’ssafetyandoperatinginstructions. Theclient’s

organizationhastheresponsibilitytodevelopandmaintainoccupationalsafetyandcreateasafety

culturewhereindividualsareexpectedtofollowsafetyinstructionsatalltimes. Anynegligenceto-

wardssafetyinstructionsorfailuretocomplywithsafepracticesshouldnotbetolerated. Itisthe

manufacturer’sresponsibilitytoproducegoodsthataresafetousewheninstructionsarefollowed.

Warranty

Forstandardwarrantytermsandconditions,seewww.vaisala.com/warranty.

Pleaseobservethatanysuchwarrantymaynotbevalidincaseofdamageduetonormalwearand

tear,exceptionaloperatingconditions,negligenthandlingorinstallation,orunauthorizedmodifica-

tions. PleaseseetheapplicablesupplycontractorConditionsofSalefordetailsofthewarrantyfor

eachproduct.

Document/Revision No. IM-EN-DD23/C	Effective: January 26, 2021

This product manual is delivered to the end-user with a Vaisala K-PATENTS product. Information in this manual is subject to change without notice. The latest manual version is always available in the Support section at http://www.vaisala.com/.

Table of contents

1	Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		1
	1.1	Disposal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	2
2	Divert Control System DD-23 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		3
	2.1	Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	3
	2.2	Divert Control Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	3
	2.3	Operator panel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	3
	2.3.1	Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	4
	2.3.2	Green indicator lights: System ok . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	5
	2.3.3	Yellow indicator lights: Warnings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	5
	2.3.4	Red indicator lights: Alarms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	5
	2.3.5	White pushbuttons: Testing and resetting . . . . . . . . . . . . . . . . . . . . . . . . .	5
	2.3.6	Header wash key: Enabling ring header wash . . . . . . . . . . . . . . . . . . . . . . .	6
	2.3.7	Emergency divert button: Manual divert . . . . . . . . . . . . . . . . . . . . . . . . . .	6
	2.3.8	External emergency divert button . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	6
	2.4	Prism wash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	6
	2.5	Indicating Transmitters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	6
3	Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		7
	3.1	Mounting prism wash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	7
	3.2	Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	8
	3.2.1	Relays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	9
	3.2.2	Divert Control Unit with AC power supply . . . . . . . . . . . . . . . . . . . . . . . .	10
	3.2.3	Divert Control Unit with DC power supply . . . . . . . . . . . . . . . . . . . . . . . .	12
	3.2.4	External power switch for Divert Control Unit . . . . . . . . . . . . . . . . . . . . .	13
	3.3	Switch inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	14
	3.3.1	External divert switch/push button: input X17 . . . . . . . . . . . . . . . . . . . . .	14
	3.3.2	External divert reset button: input X18 . . . . . . . . . . . . . . . . . . . . . . . . . . .	14
	3.3.3	Header wash key: input X19 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	15
	3.4	Remote ethernet connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	17
4	Startup	. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	19
	4.1	Divert system pre-startup checklist . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	19
	4.2	Divert Control Unit DD-23 startup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	20
5	Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		21
	5.1	Calibration lock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	21
	5.2	Divert decision rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	22
	5.3	Refractometer concentration measurement . . . . . . . . . . . . . . . . . . . . . . . .	23
	5.4	Refractometer activation for divert control . . . . . . . . . . . . . . . . . . . . . . . . .	24
	5.5	Signal difference alarm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	24
	5.6	Low alarms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	25
	5.6.1	Solids warning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	25
	5.6.2	Solids alarm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	25
	5.7	Refractometer malfunction alarm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	25

	5.8	Prism wash . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	25
6	Regular maintenance and troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		27
	6.1	Information flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	27
	6.2	Malfunctions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	27
	6.3	Diagnostic tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	29
	6.4	Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	29
	6.4.1	A question mark (?) on the refractometer display . . . . . . . . . . . . . . . . . .	29
	6.4.2	A refractometer refuses to come online . . . . . . . . . . . . . . . . . . . . . . . . . .	29
	6.4.3	No lights come up in the Divert Control Unit . . . . . . . . . . . . . . . . . . . . . .	30
	6.4.4	All lights are blinking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	30
	6.5	Ethernet strain relief for transmitters . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	30
7	Divert control logics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		33
	7.1	Safety decision logic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	33
	7.2	Divert decision logic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	34
	7.3	In operation logic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	35
	7.4	Malfunction logic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	36
	7.5	Resettable alarm logic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	37
	7.6	Refractometer difference logic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	38
	7.7	Wash arbitration logic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	39
	7.8	Wash check logic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	40
8	Remote control interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		41
	8.1	Divert Control Unit IP address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	41
	8.2	The remote interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	41
	8.2.1	Main page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	41
	8.2.2	Instrument pages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	42
	8.2.3	Diagnostics page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	42
	8.2.4	Log page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	43
	8.2.5	Parameters page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	44
9	DD-23 specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .		45
	9.1	Divert Control Unit specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	45
	9.2	Divert Control Unit spare parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	47
A	Index .	. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	49

1

1 Introduction

VaisalaK-PATENTSDigitalBlackLiquorDivertControlSystemDD-23providesadivert signal preventing black liquor with dangerously low solids to reach the black liquor burners. ThesystemisbuiltstrictlyaccordingtotheprinciplesofRecommendedGood Practice"SafeFiringofBlackLiquorinBlackLiquorRecoveryBoilers"(BLRBACApril 2015; the document is available at

http://blrbac.org/sites/default/files/Safe%20Firing%20of%20Black%20Liquor%20-%20April%202015.pdf).

The system consists of the following parts: Two Vaisala K-PATENTS Process Refractometers PR-23-SD (A & B) are installed in series in the main black liquor line. Each refractometer is complete with a sensor, Indicating Transmitter and interconnecting cables. Eachrefractometerprovidesalsotwo4–20mAoutputsignalsnotusedbythe divert control system. These can be used to give % solids output or temperature output signals. The sensors are also equipped with a steam wash nozzle although the self-cleaning sensor design may eliminate the need for prism wash.

Figure 1.1 Complete Digital Black Liquor Divert Control System DD-23

2

1.1 Disposal

When disposing of an obsolete instrument or any parts of an instrument,pleaseobservethelocalandnationalrequirementsforthedisposal of electrical and electronic equipment.

3

2 Divert Control System DD-23

2.1 Overview

Divert Control System DD-23 includes:

–Divert Control Unit

–Two PR-23-SD refractometer sensors

–TwoisolationvalvesSDIforthesensorsabovetoallowremovaloftherefractometers from a pipe with full flow and pressure. The isolation valve includes a prism washnozzleandtwocheckvalves(oneforprismwash,oneforstuffingboxflush).

–A roofed mounting plate to mount the two Indicating Transmitters and the Divert Control Unit together.

–Wiring to connect the Indicating Transmitters with the Divert Control Unit.

–Twosteamvalveswithsteamtrapsforprismwash(pneumatic+solenoidvalves).

–Two hand valves (one for prism wash, one for stuffing box flush).

–A remote operator panel facility, accessible with a web browser over Ethernet

BLRBAC (The Black Liquor Recovery Boiler Advisory Committee) recommends a spare refractometer sensor to be maintained in stock on-site.

The system can also be used with two PR-21-S process refractometers if installation oforupgradetoPR-23-SDsensorsisunfeasible. BothsensorsrequiretheirownIndicating Transmitters and the required interconnecting cables between the sensor and transmitter, but otherwise the installation is similar to the PR-23-SD based one.

2.2 Divert Control Unit

TheDivertControlUnitiscontainedinanenclosurewiththesamedimensionsasthe refractometer transmitter enclosure. The control unit includes:

–An operator with system state indicators and pushbuttons

–Relay outputs for connecting to the control system

–Contact inputs for external control

–Ethernet interface for remote operator panel

2.3 Operator panel

The operator panel has a clear layout and the operator can see all information at one glance. Thedivertdecisioniscontrolledfromtheoperatorpanelwhichprovidesdoubledsecurity, sinceinformationisshown both asLED indicationin the Divertcontrol unit and as a diagnostic messages in the Indicating Transmitters. The same information is also available through the remote operator panel.

4

2.3.1 Overview

Red indicator lights (alarms)

Yellow indicator lights (warnings)

Green indicator lights (all well)

White pushbuttons

Red push-button

Figure 2.1 DD-23 operator panel

The three top rows on the operator panel consist of indicator lights. The green A IN OPERATION andBINOPERATION lightsarealsopushbuttonsusedtoincludetherefractometersintheDivertsystem. BelowthelightstherearepushbuttonsandtheHEADER WASH key key used to operate the system.

The indicator lights on the operator panel are arranged like traffic lights: top row is red for alarm, middle row is yellow for warning and bottom row is green for "system ok". When the system is running normally, only the row of green lights is lighted.

The white LIGHT TEST button is used to check that all the LEDs behind the indicator lights are working. It also verifies the data processing system in the control unit. The other two white push buttons, ALARM RESET and DIVERT RESET can be used to reset the system back to normal after all problems have been fixed. The HEADER WASH key enables the use of ring header washing with water, when set to ON.

The big red EMERGENCY DIVERT push button is used to manually initiate divert in an emergencysituation. Anexternalpushbuttoncanalsobeconnectedtoaswitchinput in the control unit as External Emergency Divert Button, see Section 2.3.8.

5

2.3.2 Green indicator lights: System ok

Eachrefractometerhasagreenoperatinglight– A IN OPERATION andB IN OPERATION – to let the operator know when he can rely on the refractometer measurement. A refractometer can only influence the divert decision and activate warnings and alarms when it is in divert operation, i.e. when its green operating light is lighted.

WhenDIVERTiseffective,thesystemcanberesettonormaloperationonlywhenSAFE

SOLIDS is lighted.

2.3.3 Yellow indicator lights: Warnings

The SOLIDS WARNING light indicates a black liquor concentration of below warning limit (by default at 60%). This warning can be activated by either refractometer.

TheA&B DIFFERENCE lightislightedwhentherefractometerreadingsdifferbyatleast

2%. This warning is only be initiated if both refractometers are operating.

If the yellow MALFUNCTION light is switched on, some part of the system – a refractometer, a transmitter or the control unit – is malfunctioning. A list of malfunctions and critical malfunctions is given in Section 6.2. If a critical malfunction occurs in a sensor or a transmitter, the malfunctioning refractometer is automatically removed from divert operation (its operating light is also switched off). Check the reason for themalfunctionandcorrecttheproblem(seeSection6.4)beforereturningtherefractometer back to divert operation.

2.3.4 Red indicator lights: Alarms

The black liquor SOLIDS ALARM is lighted when the concentration reading goes below alarmlimit(bydefaultbelow58%). Thisalarmcanbeactivatedbyeitherrefractometer depending on the operation rule setting.

The DIVERT light is switched on when the SOLIDS ALARM is activated. The DIVERT light indicates divert status of the divert relay. The relay is inactive in the divert position, because then a power failure will give a divert decision signal to the system.

The OVERRIDE light is lighted to indicate that no automatic divert will happen as long as the system is in the header wash state (see Section 2.3.6).

2.3.5 White pushbuttons: Testing and resetting

The LIGHT TEST button switches all 12 lights on. The ALARM RESET button resets the alarm lights.

6

2.3.6 Header wash key: Enabling ring header wash

The header wash key function is a 3-level procedure which can be used when ring header washing with water is needed. When the HEADER WASH key is switched to ON position and information from black liquor guns switch inputs connected in series tells that guns are out from recovery boiler, then a ring header wash can be done without activating divert.

Pushing the EMERGENCY DIVERT button will always initiate divert regardless of the header wash functionality.

2.3.7 Emergency divert button: Manual divert

The EMERGENCY DIVERT push-button is used to manually initiate divert in an emergency situation.

2.3.8 External emergency divert button

Anexternal(remote)pushbuttoncanalsobeconnectedtoaninputinsidetheControl

Unit, see Figure 3.4.

Note: External emergency divert button must be normally closed (NC). Opening the circuit will initiate divert.

2.4 Prism wash

The wash parameters for the sensors are set through each transmitter (Section 2.4). Thetransmitterscontainarelayforprismwash. TofollowtheBLRBACrecommendationnottowashbothprismsatthesametime,theDivertControlUnitimplementsan interlock which prevents the instrument from washing both sensors simultaneously.

2.5 Indicating Transmitters

MechanicallytheIndicatingTransmittersshippedwithaDD-23arethesamethanPR- 23 Indicating transmitter DTR. The transmitter only allows single sensor connection and a special DD-23 transmitter software is used for the divert system. When divert software is 2.01 or newer, Indicating Transmitter software version must be 4.12 or newer.

For more information on the basic functions of Indicating Transmitter, please see the

PR-23 user guide, chapters 4 and 11.

7

3 Mounting

For mounting of the process refractometers and the isolation valves, consult the separate Process Refractometer PR-23 user guide.

Figure 3.1 Mounting the divert control system

Part	Specifications	Supplied by	Qty
1	PR-8230 interconnecting cable between sensor and transmitter	Vaisala	2
2	Ethernet cable divert 0.7 m (2.3 ft)	Vaisala	2
3	Solenoid valve cable multicore 2x1 1.5 mm2 (AWG 16), max. 100 m (330 ft)	Customer	2
4	Divert control cable	Customer	1
5	Power supply multicore 3x1 1.5 mm2 (AWG 16)	Customer	5
6	Relay information to DCS	Customer	3
7	Junction box	Customer	2

Table 3.1 Mounting the divert control system

3.1 Mounting prism wash

Vaisalarecommendstouseasteamtrapinsteadofapreconditioningvalvetoremove condensate from the steam line.

8

3.2 Wiring

For wiring for complete system, see Figure 3.2 which shows the connections to the indicating transmitters and to steam washing. Figure 3.4 has information of all connections to the divert control unit.

Figure 3.2 Transmitter wiring cables and connections

9

3.2.1 Relays

Warning! Connect only either

ACorDC power to relays!

X

110-230AC 110-230AC

+24VDC +24VDC

+24VDC 110-230AC

You can connect AC power to both relays or DC power to both relays, but never connect AC in one and DC in the other relay.

Figure 3.3 Relay warning

Relay 1 NORMAL/DIVERT information

Relay 2 NORMAL/DIVERT information

Relay 3 SOLIDS WARNING: when one of the refractometers goes lower than the solids warning limit, typically 60% or higher. See Section 5.6.1.

Relay 4 SOLIDSALARM:whenoneoftherefractometersgoeslowerthanthesolids alarm limit, typically 58% or higher. See Section 5.6.2.

Relay 5 Refractometersignaldifferencewarning: whentherefractometerreadings have more than 2% difference in concentration. See Section 5.5.

Relay 6 Horn relay: connection to the audible alarm. See Section 7.5. Relay 7 Header wash key information. See Section 3.3.3.

Relay 8 Refractometer A malfunction information. See Sections 6.2 and 7.4. Relay 9 Refractometer B malfunction information. See Sections 6.2 and 7.4. Relay 10 Information on if refractometer A is active in the Divert Control System or

dropped off.

Relay 11 Information on if refractometer B is active in the Divert Control System or dropped off.

10

3.2.2 Divert Control Unit with AC power supply

Figure 3.4 Divert Control Unit internal wiring for AC power supply

11

	Connector	Function	Electrical specification
	X1	Relay 1: Normal/Divert #1
	X2	Relay 2: Normal/Divert #2
			AC: Max 3 A, max 250 VAC,
	X3	Solids warning
			max 1250 VA
	X4	Solids alarm
	X5	Refractometer difference warning	DC:Max3AatDCvoltageof30VDC,
			max 0.2A at DC voltage of 125VDC
	X6	Horn relay
	X7	Header wash/Override active
	X8	No malfunction A	<![if ! IE]> <![endif]>NO	<![if ! IE]> <![endif]>COM	<![if ! IE]> <![endif]>NC		RELAY CON
	X9	No malfunction B					(X1 - X11)
	X10	Refractometer A in divert use
	X11	Refractometer B in divert use
	X12	For DD23 internal use only
	X13	Power L (100-240 VAC), 50-60 Hz,
		N, protective earth
	X17	Switch input 1: External divert	5 VDC (out) and switch inputs are
		switch	galvanically isolated
			Power max 1 W
	X18	Switch input 2: External divert
			<![if ! IE]> <![endif]>+5V	<![if ! IE]> <![endif]>IN
		reset			SWITCH IN
					(X17 - X19)
	X19	Switch input 3: Header wash
	X21	For DD23 internal use only

Table 3.2 Connectors for AC power supply

Connectorplugs forX1 throughX11 and X17 throughX19: Stripping length for wires 7 mm, torque 0.22 Nm to 0.25 Nm.

TheprimaryACpowerisconnectedtoaseparateterminalstripX13. ThethreeterminalsaremarkedL,Nand . Theprotectiveearthisdirectlyconnectedtotheexposed metal parts of DD-23. Wiring to terminals should be min. 1.5 mm2. The fuse voltage shouldbe250V,max. size10Aandfusespeedslow. Torqueusedis0.5Nmto0.6Nm. Stripping length is 8 mm for wires.

The protective fuse in the building system shall comply with the local requirements.

L N

Yellow-green

Blue

Brown

Figure 3.5 Power terminals for AC power supply

12

3.2.3 Divert Control Unit with DC power supply

Warning! ItemsDD-23-M-GP-DCandDD-23-U-GP-DCarePELVdevices. Seetype label for supply voltage specifications. Connect the protective grounding to the same grounding potential that is used by the external power supply.

<![if ! IE]>

<![endif]>24 VDC

Figure 3.6 Divert Control Unit internal wiring

for DD-23-M-GP-DC and DD-23-U-GP-DC