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L91A,B,D PROPORTIONING PRESSURETROL® CONTROLLERS
60-2152—08 2
ORDERING INFORMATIONWhen purchasing replacement and modernization products from your TRADELINE® wholesaler or distributor, refer to the
TRADELINE® Catalog or price sheets for complete ordering number.
If you have additional questions, need further information, or would like to comment on our products or services, please write or
phone:
1. Your local Honeywell Automation and Control Products Sales Office (check white pages of your phone directory).
2. Honeywell Customer Care
1885 Douglas Drive North
Minneapolis, Minnesota 55422-4386
In Canada—Honeywell Limited/Honeywell Limitée, 35 Dynamic Drive, Toronto, Ontario M1V 4Z9.
International Sales and Service Offices in all principal cities of the world. Manufacturing in Australia, Canada, Finland, France,
Germany, Japan, Mexico, Netherlands, Spain, Taiwan, United Kingdom, U.S.A.
SPECIFICATIONSModels (Table 1):
L91A: Single potentiometer; nonadjustable proportioning
range.
L91B: Single potentiometer; adjustable proportioning range.
L91D: Two potentiometers allow unison control of motors;
adjustable proportioning range.
Electrical Rating: 24 Vac.
Potentiometer Action: Wiper moves toward W on pressure
rise, toward B on pressure fall. Potentiometer is field
replaceable.
Potentiometer Resistance: 140 ohms (nominal) for L91A, B,
and D models.
Pressure Sensing Element: Brass bellows, 10-300 psi
models phos-bronze bellows.
Minimum Ambient Temperature: 32° F (0° C)
Maximum Ambient Temperature: 150° F (66° C)
Adjustment Means: Screws on controller case top; knurled
knob for main scale setting on 10 to 300 psi (0.07 to 2.07
MPa) models.
Setpoint: At low pressure end of proportioning (throttling)
range.
Main Scaleplate: Marked in both U.S. customary (oz/sq. in,
psi, or in. Hg) and metric (kPa, MPa, or mm Hg) units.
Proportioning Range Scaleplate (L91B,D only): Gradu-
ated from A to F with a MIN (minimum) value below A.
(See Table 2 for the value of each division.)
Mounting Means: Fitting on bellows has 1/4 - 18 NPT
threads (external on 0 to 16 oz/sq. in., 0 to 4 psi, and 0 to
15 psi models; internal on all other models) for mounting on
a pipe or steam trap (siphon loop).
NOTE: Some models are available with 1/4 - 19 BSP-TR
internal threads; see Table 1.
Also can be surface mounted by screws through two knockout
holes in case back.
Table 1. Models available.
Operating RangesaProportioning (Throttling) Range at Midscale
Maximum Surge
Pressure
Model
U. S.
Customary
Units Metric Units
Potentiometer
Part No.bAdjustable
U. S.
Customary
Units Metric Units psi kPa
L91A 0 to 15 psi 0 to 103 kPa 23176CB No 0.5 psi 3.4 kPa 25 172
5 to 150 psi 0.03 to 1.03 MPa 23176CB No 5 psi 0.03 MPa 225 1551
10 to 300 psib0.07 to 2.07 MPa 23176CB No 12 psi 0.08 MPa 350 2413
L91B 0 to 15 psi 0 to 103 kPa 23176CF Yes 1.5 to 12 psi 10 to 83 kPa 25 172
5 to 150 psic0.03 to 1.03 MPa 23176CB Yes 5 to 23 psi 35 to 160 kPa 225 1551
10 to 300 psic0.07 to 2.07 MPa 23176CB Yes 12 to 48 psi 85 to 330 kPa 350 24 13
10 to 300 psi 0.07 to 2.07 MPa 23176CF Yes 30 to 110 psi 0.21 to 0.76 MPa 350 2413
L91D 0 to 15 psi 0 to 103 kPa 23176CF Yes 1.5 to 12 psi 10 to 83 kPa 25 172
5 to 150 psic0.03 to 1.03 MPa 23176CF Yes 13 to 52 psi 0.09 to 0.36 MPa 225 1551
10 to 300 psic0.07 to 2.07 MPa 23176CF Yes 30 to 110 psi 0.21 to 0.76 MPa 350 2413