Honeywell L91B, L91D, L91F User Manual

Honeywell

L91

PROPORTIONING

PRESSURETROLCONTROLLERS

L91

PROPORTIONING PRESSURETROL CONTROLLERS ARE

SERIES 90 MODULATING PRESSURE CONTROLLERS THAT

PROVIDE DIRECT CONTROL OF MODULATING MOTORS OR

VALVES USED ON AUTOMATIC BURNERS OR STEAM HEAT-

ING SYSTEMS.

0 L91A

Models available for pressure systems up to 300 psi [2066

kPa].

l These controllers may be used with steam, air, noncombust-

ible gases, or other fluids noncorrosive to the brass or bronze (300 psi models) bellows.

0 L91B

0 L91D

0 L91F

phos-

Wiper on the controller potentiometer moves in response to

pressure changes.

L91

D has 2 potentiometers for unison control of 2 motors.

L91F

has a fixed resistor and a manually-adjusted trim potentiometer in series with the controller potentiometer; for special applications in electronic bridge circuits.

l LSlB,D, and F models have an adjustable proportioning

(throttling) range to allow selection of desired pressure control range.

Adjustments are made by screws on top of case.

Large, easily-read scaleplates are marked in both customary

(or/in.*, psi, or in. Hg) and metric

Steel case has clear plastic cover so that pressure settings

and potentiometer action can be observed.

Fitting with

Controller can also be surface mounted by screws through

holes (knockouts) in back of case.

l/4-16

NPT threads provides rapid installation.

(kPa, MPa, or mm Hg) units.

0.03 to 1.03

to 300

L91 Fa

ps.0

0 to 15 psi

5 to 150 psi

0.07

2.07

0 to 103

kPa

0.03 to 1.03 MPa

SPECIFICATIONS

TABLE I-MODELS AVAILABLE

MPa

23176CF

Yes Yes Yes

30 to 110 psi

1.5 to 12 psi 13 to 52 psi

0.09 to 0.36

0.21 to 0.76 MPa

0.09 to 0.36

10 to 63

MPa

kPa

MPa

350 2413

225

172

1551

aScaleplates are marked in both customary bModels available with or without steam trap (siphon loop).

‘Includes steam trap (siphon loop).

dModel

available with

eL91F

models have onefixed resistor and one manually-adjustable trim potentiometer in series with thecontroller potentiometer. Varidus combinations of resistance

values and locations of the fixed resistor and trim potentiometer are available. See Table II.

fLength of active winding is gSee

Table II for potentiometer part number.

D.A.

12-66*

l/4

in. BSP-TR internal threads (British Standard Pipe Threads) for mounting.

7/64

in.

(ozlin?,

[2.8

mm] for Part No.

psi, or in. Hg) and Metric (kPa, MPa. or mm Hg) units.

23176CB,

and

l/4

in.

[6.4

mm] for Part No. 23176CF.

Form Number 65-0059

@Honeywell Inc. 1966

PROPcJRTlONlNG RANGE

ADJUSTING SCREW

(L91B.D.F.ONLY)

MAIN

SCALE

ADJUSTING

MAIN SCALE SETTING INDICATOR

KNURLED ADJUSTMENT KNOB ON IO TO

[0.07

TO 2.07

CONTROLLER POTENTIOMETER(S)

MPa,

MODELS.

IM POTENTIOMETER JUSTING

SCREW

POTENTIOMETER

WIPER ARM(S)

PROPORTIONING

SCALEPLATE

(L91B,D,F

PROPORTIONING

INDICATOR (L91B.D.F ONLY)

-BELLOWS HOUSING

300

PSI

ONLY)

El275

FINISH: Gray. MAIN SCALEPLATE: Marked in both customary (oz/in.*, psi, or in.

Hg) and Metric

PROPORTIONING RANGE SCALEPlATE

(kPa. MPa.

or mm Hg) units.

(L919, D,

and F only): graduated from A to F with a MIN (minimum) value below A. (See Table Ill for the value of each division.)

MOUNTING MEANS: Fitting on bellows has

(external on 0 to 16

oz/in2,

0 to 4 psi, and 0 to 15 psi models;

l/4-18

NPT threads

internal on all other models) for mounting on a pipe or steam trap

(siphon loop).

l/4-19

NOTE: Some models are available with

threads: see Table

BSP-TR internal

Also can be surface mounted by screws through 2 holes (knockouts) in back of case.

TABLE

II-L91

F RESISTANCE VALUES AVAILABLE

Blega

InB lega

lnwlegb 380.0

aAvailable

for Oto 15 psi

bAvailable

for Oto 15 psi IOto 103

11.2

23367F 3/16

17.6

233676 3/16

23176- l/4

[Ot o

103

kPa]

4.8

470

4.8

870

6.4

2080

models only.

kPa]

and 5to 150 psi

518

t2ohms,

R-B

942+2ohms,R-B

2515 f

lOohms,

[0.03

to 1.03

MPa]

models. 'Nominal resistancevalues.

FIG.

SETTING AN

L91

PROPORTIONING

PRESSURETROI

CONTROLLER.

MODELS:

LSlA-single

potentiometer; nonadjustable proportioning

range.

L91

B-single potentiometer; adjustable proportioning range.

L91D-2

potentiometers allow unison control of 2 motors;

adjustable proportioning range.

L91

F-single potentiometer; adjustable proportioning range; fixed resistor and manually-adjustable trim potentiometer in

series with controller potentiometer. ELECTRICAL RATING: 24 POTENTIOMETER ACTION: Wiper moves toward

rise; toward

“6”

Vat.

“w”

on pressure

on pressure fall. Potentiometer is field

replaceable.

POTENTIOMETER RESISTANCE: 140 ohms (nominal) for

and D models; see Table II for

L91

F models.

LSlA,B,

PRESSURE SENSING ELEMENT: Phos-bronze bellows. MAXIMUM AMBIENT TEMPERATURE: 150 F [66 C]. MINIMUM AMBIENT TEMPERATURE: 32 F [0 C].

ADJUSTMENT MEANS: Screws on top of controller case; knurled

knob for main scale setting on 10 to 300 psi

[0.07

to 2.07 MPa]

models.

SET POINT: At low pressure end of proportioning

(throttling) range.

WEIGHT: 116.15 oz. [0.88 kg].

eManually

adjustable trim potentiometer is

models. With zero pressure on the bellows, adjust the trim potentiometer to obtain the resistance values listed between terminals R and 8, or between terminals R and W, as indicated.

100

ohms (nominal)

in all

L91F

TABLE III-APPROXIMATE VALUE OF EACH DIVISION

(A TO

B TO C. etc.) ON PROPORTIONING (Throttling)

RANGE SCALEPLATE

OPERATING

RANGE

(L919,D.F

VALUE OF EACH

only)

DIVISION

CUSTOMARY UNITS METRIC UNITS CUSTOMARY UNITS METRIC UNITS

2 to

5 to 156

5to

10to300

(L918

10to

(LSlB,D

(L91B)

(LSlD,i)

with 7/64 in.

pot.)

in. pot.)

50 psi 14to

psi

150

osi

psi

300

psi

with

l/4

345

kPa 4.7psi

10.03to

1.03 MPal

10.03to

1.03

MPal

0.07to2.07 MPa

7.8psi

6.7

psi

16.4psi

13.8psi

32.4

kPa

0.054

MPa

0.046

MPa

0.113 MPa

0.095 MPa

PRINTED IN U.S.A.