Page 1
DESCRIPTION
The RL 147 Positioning Relay is a compact pneumatic device
designed to provide positive positioning of a pneumatic valve
or damper actuator. The positioner provides supply air
pressure against the actuator diaphragm to initiate stem or
shaft movement. The actuator spring reverses the stem or
shaft movement.
FEATURES
•
Rapid response
•
Good repeatability
•
Adjustable start point pressure
•
Adjustable span
•
Low air consumption
Technical Instruction
Document Number 155-038
RL 147-2
May, 1996
RL 147 POSITIONING RELAY
Figure 1. The RL 147 Positioning Relay mounted on a
No. 6 Damper Actuator.
SPECIFICATIONS
Operating:
Ambient Temperature Range
Storage...................................... -20 to 160°F (-29 to 71°C)
Operation .......................................35 to 160°F (2 to 71°C)
Maximum Pilot Signal Pressure .....................30 psig (207 kPa)
Maximum Supply Air Pressure.......................60 psig (413 kPa)
Start Point Adjustment Range.................3-10 psig (21-69 kPa)
Operating Span Adjustment Range.........3-12 psig (21-83 kPa)
Response.................................1/10 psi Input change (0.7 kPa)
Air Capacity @ ∆P = 2 psi (14 kPa) ............ 410 scim (112ml/s)
Air Consumption............................................. 40 scim (11 ml/s)
Table 1. Product Numbers for Positioning Relay and Mounting Kits.
Description of Actuator Type Order Numbers Reference
No. 3 Damper Actuator For actuators manufactured after 1/1/93 147-2000 147-104 7
No. 4 Damper Actuator 147-2000 147-314 7
No. 6 Damper Actuator 147-2000 147-276 8
8" Valve Actuator
For Flowrite actuators manufactured after 3/1/96
For Model 3 Flowrite actuators manufactured between 3/1/93
and 1/1/96
For Models 1 and 2 Flowrite actuators. Also order spring arm
# 147-307 for use with VF 591 5” and 6” balanced valves
12” Valve Actuator
For Flowrite actuators manufactured after 1/1/96
For Flowrite actuators manufactured between 3/78 and 1/1/96 147-2000 147-311 11
For Super Flowrite and 12” Flowrite actuators manufactured
before 3/78
PRODUCT NUMBERS
SPECIFICATIONS, Continued
Physical:
Air Connections ........................................... 1/8" (3.2 mm) NPT
Body Materials ....................................................................Zinc
Cover.......................................................... Electro Plated Steel
Dimensions .................................................................Figure 14
Shipping Weight w/Kit........................................... 2 lb. (0.9 Kg)
Positioning Relay Mounting Kit Page
599-00426
Contains both relay and mounting kit
147-2000 147-333 8
147-2000 147-277 10
599-00423
Contains both relay and mounting kit
147-2000 147-279 10
Refer to Table 1
9
9
.
Landis & Gyr, Inc.
Page 2
Technical Instruction Landis & Gyr, Inc.
RL 147-2 Page 2
APPLICATION
The Positioning Relay is recommended for damper actuator
and valve applications where rapid speed of response and/or
repeatability of stem position is needed to obtain good system
operation. It can be used to reduce the span of controlled
devices to permit sequencing. It can also be used to increase
the close-off force of a normally open actuator without
affecting its spring span. This happens because the positioner
uses full supply air pressure to position the actuator.
The spring range of the actuator does not effect the operation
of the positioner. Therefore, it is recommended that an
actuator with a high spring range, such as 8 to 13 psig (55 to
90 kPa), be selected. This combination has the high return
force of the actuator spring plus the high forward force
available from the positioner.
A positioning relay can be connected to handle up to four
identical No. 6 damper actuators or up to six identical No. 4
damper actuators provided the following conditions are met.
All actuators must operate the same damper, and no more
than 100 feet of 1/4” (6.4 mm) O.D. tube is used to connect
them. Remember all actuators connected this way must be
identical (i.e., same size, spring range, stroke, etc.).
The positioning relay is single acting and is primarily intended
for use on actuators with an integral spring to return the
actuator shaft to the normal position. Applications with a
double acting (spring-less) actuator require a reversing relay to
provide the additional control signal.
OPERATION
A rise in thermostat pressure will unbalance the lever
assembly. Refer to Figure 2. The shaft movement, through the
spring arm, increases tension on the feedback spring to bring
the lever assembly again into balance. A drop in thermostat
pressure will unbalance the lever assembly in the opposite
direction to exhaust air from the actuator until a new balance
position is reached.
The positioning relay start point is adjustable. The start point
adjustment nut shown in Figure 2 is used to set the start point
pressure. The span adjustment screw tab location on the
feedback arm and the feedback spring location on the spring
guide determine the span setting of the relay.
Figure 2. Operation Schematic.
Page 3
RL 147 POSITIONING RELAY Technical Instruction
155-038 Page 3
Figure 3. Construction of the RL 147 Positioning Relay.
Item
1 147-255 Cover 1 Steel
2 – Plate 1 Zamac Die Casting
3 – Lever Assembly 1
4 – #8-32 Cover Screw 1 Steel
5 – Washer 1 Rubber
6 147-273 Pivot Screw 2 Stainless Steel
7 – #8-32 x 1/2 “ Lg. Dual Pt. Set Screw 1 Steel
8 – #8-32 Palnut 1 Steel
9 – Diaphragm Assembly 1
10 – Start Point Adjustment Nut 1 Brass
11 – Start Spring 1 Music Wire
12 – Supply Valve Seat 1 Brass
13 – Supply Valve Spring 1 Phosphor Bronze
14 – Ball Assembly 1 Stainless Steel
15 – Gasket 1 Fairprene
16 – Bleed Port 1 Brass
17 – Base 1 Zamac Die Casting
18 034-048 #6-32 x 5/8” Lg. Bind Hd Screw 2 Brass
19 147-297 Spring Guide 1 Steel
20 034-067K Span Adjustment Screw 1 Steel
21 – Feedback Arm 1 Steel
Replacement
Part No.
Description
No.
Req’d
Material
Page 4
Technical Instruction Landis & Gyr, Inc.
RL 147-2 Page 4
For spans of 11 psig or 12 psig (76 or 83 kPa)
CALIBRATION
Complete calibration instructions are included with each
positioning relay.
1. Check that you have the correct feedback spring(s)
attached.
2. Identify the desired operating span and the start point
pressure.
NOTE: In some cases, the actuator stem travel or stoke
is not identical to the nominal value of the relay feedback
spring. Refer to Calculating the Span Setting on page 5
to determine the span setting on the feedback arm.
1. Move the span adjustment tab to the 10 setting on the
feedback arm. Follow steps 2 and 3 above.
2. Move the feedback spring one hole away from the
standard location for a span of 11 psig (76 kPa) and two
holes away from the standard spring location for a 12 psig
(83 kPa) span. Refer to Figure 4.
3. Follow steps 4 and 5 above.
Adjusting the Start Point. Refer to Figure 6.
The positioning relay can be adjusted to start actuator movement at pressures between 3 and 10 psig (21 and 69 kPa).
1. Remove the relay cover.
2. Attach tubing with a pressure gauge and squeeze bulb to
the "T" port. Supply air should be attached to the "S" port.
The "M" port should be attached tot he connector on the
actuator.
3. Using the squeeze bulb, apply pressure to the relay.
Watch the valve stem or actuator shaft to see when it
begins to move. Check your pressure gauge; this is your
start point pressure.
4. If this is not the desired start point pressure, turn the start
point adjustment nut (Figure 5) clockwise to increase the
start point pressure and counterclockwise to decrease the
pressure.
5. Repeat steps 3 and 4 until the stem or shaft begins to
move at the desired pressure.
Figure 4. Span Adjustment.
Shown at Span Setting 8.
Setting the Span. Refer to Figure 4.
The positioning relay operating span can be set for spans of
3 psig through 12 psig (21 kPa to 83 kPa).
For spans of 3 psig through 10 psig (21 to 69 kPa)
1. Check that the feedback spring is attached to the spring
guide in the hole across from the span adjustment screw.
This is identified as the standard location in Figure 4.
2. With a screwdriver, loosen the span adjustment screw.
Move the spring guide on the feedback arm until the span
adjustment tab is at the desired span setting reference
number.
NOTE: The line to the left of the number is the setting.
3. Tighten the span adjustment screw.
4. The feedback spring must be parallel to the actuator shaft
or valve stem. Use open end wrenches to loosen the hex
nuts holding the spring arm in position on the shaft or
stem. Align the feedback spring and tighten the hex nuts.
5. The feedback spring should have no slack or no stretch in
it. Adjust the wing nuts and adjustment nut, if necessary
Figure 5. Start Point Adjustment.
Adjusting the Span
1. Using the squeeze bulb, apply pressure to the relay. Note
the pressure at which the stem or shaft begins to move.
2. Continue to apply pressure until the stem or shaft
completes its full stroke. Note the pressure.
3. The difference between the two pressures is the span.
4. If the span is not the desired span, move the spring guide
to a higher reference number to increase the span or
lower number to decrease the span. Refer to Figure 4.
5. Repeat steps 1 through 4 until you get the desired span.
Page 5
RL 147 POSITIONING RELAY Technical Instruction
155-038 Page 5
6. If you have moved the spring guide, you will need to
adjust the spring arm so that the spring is parallel to the
stem or shaft.
7. Check the feedback spring. There should be no slack or
no stretch in it. Adjust the wing nuts and adjustment nut, if
necessary.
8. Fasten the relay cover. Fill in the information on the
calibration label.
Calculating the Span Setting
1. Identify the valve stem from Table 2 or 4. If the stroke of
the No. 6 damper actuator has been changed from the
factory setting refer to Table 7.
2. If your stem travel matches the nominal spring travel listed
in Table 2 there is no need to calculate a new span
setting.
3. If your stem travel does not match the nominal spring
travel listed in Table 2, choose the spring(s) whose
maximum allowable travel is equal or greater than your
actual stem travel.
4. Calculate the span setting with the formula below.
Formula for Span Setting
Span
Setting
= Desired span X
Nominal spring travel
Actuator stroke
Example:
Determine the span setting for a valve having desired
span of 5 psig and 5/16" stroke.
Table 2. Spring Selection.
Spring Travel Range Recommended Springs
Nominal
in. (mm)
Max. Allowable
in (mm)
Part No. Size & Color
5/32 (5.0) 1/4 (6.4) 147-298 Small Green
1/4 (6.4) 3/8 (9.5) 147-289 Small Cadmium Plate
3/8 (9.5) 1/2 (13) (2)147-298 Small Green
3/4 (19) 1 (25) 147-290 Small Red
1 (25) 1-1/4 (32) 147-291 Long Green
1-1/4 (32) 1-5/8 (41)
147-289
plus
147-291
Small Cadmium Plate
plus
Long Green
1-1/2 (38) 2 (51) (2) 147-290 Small Red
1-3/4 (44) 2-1/4 (57)
147-290
plus
147-291
Small Red
plus
Long Green
2 (51) 2-1/2 (64) (2) 147-291 Long Green
2-3/8 (60) N/A 147-105 2” Red
3 (76) 3-1/4(83) 147-292 Long Cadmium Plate
3-3/4 (95) 4 (102) 147-301 3” Red
4 (102) 4-1/4 (108) 147-293 Blue
4 (102) 6 (152) 147-313 Zinc Pl. or Yell. Chr.
7 (178) 12-1/4 (311) 147-330 Zinc Plate
Select a spring with a maximum allowable range equal to or
larger than the stroke. Use the 1/4" spring with a 3/8"
maximum allowable travel range. Refer to Table 2.
Span
Setting
= 5 X
0.25
0.312
= 4
Set the span adjustment tab to line 4 on the feed back arm to
provide a 5 psig span for this valve.
Table 3. Stem Travel for VP 591 Bronze Body Valves.
Line Size Stem Travel inches (mm)
in. (mm) Single
Double Seat WM
Seat
1/2 (13) 3/8 (9.5) — 1/8 (3.2)
3/4 (19)
3/4 (19)
— 3/16
(4.8)
1 (25)
1-1/4 (32)
3/4 (19)
1 (25)
3/16 (4.8) 1/4 (6.4)
1/4 (6.4) 5/16
(7.9)
1-1/2 (38)
1 (25)
1/4 (6.4) 5/16
(7.9)
2 (51) 5/8 (16) 3/8 (9.5) NO.
5/16 (7.9) N.C.
5/16
(7.9)
Page 6
Technical Instruction Landis & Gyr, Inc.
RL 147-2 Page 6
Table 4. Stem Travel listed by 591 or 593 Flowrite Valve Product Number.
Flowrite
Product
Number
591-6480 5/8 (16)
591-6490 3/4 (19)
591-6540 5/8 (16)
591-6600 1/8 (3.2)
591-6610 3/16 (4.8)
591-6620 1/4 (6.4)
591-6630 5/16 ((7.9)
591-6640 5/16 ((7.9)
591-6650 5/16 ((7.9)
591-6720 5/8 (16)
591-6730 3/4 (19)
591-6740 1 (25)
591-6840 3/8 (9.5)
591-6850 9/16 (14)
591-6860 9/16 (14)
591-6870 5/16 ((7.9)
591-6880 9/16 (14)
591-6890 9/16 (14)
591-6900 1/4 (6.4)
591-6910 1/4 (6.4)
591-6920 5/16 (7.9)
591-6930 9/16 (14)
591-6940 3/16 (4.8)
591-6950 1/4 (6.4)
591-6960 1/4 (6.4)
591-6970 3/8 (9.5)
591-6980 3/16 (4.8)
591-6990 1/4 (6.4)
591-7000 1/4 (6.4)
591-7010 5/16 ((7.9)
591-7020 3/16 (4.8)
591-7030 1/4 (6.4)
591-7040 1/4 (6.4)
591-7050 3/8 (9.5)
591-7060 3/8 (9.5)
591-7070 9/16 (14)
591-7080 9/16 (14)
591-7090 3/16 (4.8)
591-7100 5/16 ((7.9)
591-7110 9/16 (14)
591-7870 3/4 (19)
Stem
Travel
in. (mm)
Flowrite
Product
Number
591-7871 3/4 (19)
591-7872 1 (25)
591-7873 1 (25)
591-7874 1 (25)
591-7875 3/4 (19)
591-7876 3/4 (19)
591-7877 1 (25)
591-7878 1 (25)
591-7879 1 (25)
591-7971 3/8 (9.5)
591-7972 3/4 (19)
591-7973 3/4 (19)
591-7974 1 (25)
591-7975 1 (25)
591-7976 1 (25)
591-7977 3/8 (9.5)
591-7978 3/4 (19)
591-7979 3/4 (19)
591-7980 1 (25)
591-7981 1 (25)
591-7982 1 (25)
591-8016 5/8 (16)
591-8017 5/8 (16)
591-8018 3/4 (19)
591-8019 3/4 (19)
591-8020 1 (25)
591-8021 1 (25)
591-8028 5/8 (16)
591-8029 3/4 (19)
591-8030 1 (25)
591-8071 3/8 (9.5)
591-8072 3/4 (19)
591-8073 3/4 (19)
591-8074 1 (25)
591-8075 1 (25)
591-8076 1 (25)
591-8077 3/8 (9.5)
591-8078 3/4 (19)
591-8079 3/4 (19)
591-8080 1 (25)
Stem
Travel
in. (mm)
Flowrite
Product
Number
591-8081 1 (25)
591-8082 1 (25)
591-8330 5/8 (16)
591-8331 5/8 (16)
591-8332 3/4 (19)
591-8336 5/8 (16)
591-8337 5/8 (16)
591-8338 3/4 (19)
591-8339 3/4 (19)
591-8340 1 (25)
591-8341 1 (25)
591-8342 1-1/2 (38)
591-8344 1-1/2 (38)
591-8350 1-1/2 (38)
591-8351 1-1/8 (29)
591-8352 1-1/8 (29)
591-8353 1-1/8 (29)
591-8354 1-1/8 (29)
591-8355 1-1/8 (29)
591-8356 1-1/8 (29)
591-8357 1-1/8 (29)
591-8358 1-1/4 (32)
591-8359 1-1/8 (29)
591-8360 1-1/2 (38)
591-8362 1-1/2 (38)
591-8364 1-1/8 (29)
591-8365 1-1/8 (29)
591-8366 1-1/8 (29)
591-8367 1-1/8 (29)
591-8368 1-1/8 (29)
591-8369 1-1/8 (29)
591-8370 1-1/8 (29)
591-8371 1-1/8 (29)
591-8372 1-1/4 (32)
591-8373 1-1/4 (32)
591-8374 1-1/2 (38)
591-8376 1-1/2 (38)
591-8378 1-1/4 (32)
591-8379 1-1/4 (32)
591-8380 1-1/4 (32)
Stem
Travel
in. (mm)
Flowrite
Product
Number
593-8381 1-1/4 (32)
593-8382 1-1/2 (38)
593-8383 1-1/2 (38)
593-8388 3/4 (19)
593-8389 3/4 (19)
593-8390 3/4 (19)
593-8391 3/4 (19)
593-8392 1-1/8 (29)
593-8393 1-1/8 (29)
593-8394 1-1/4 (32)
593-8395 1-1/4 (32)
593-8396 1-1/4 (32)
593-8397 1-1/4 (32)
593-8398 1-1/4 (32)
593-8399 1-1/4 (32)
593-8400 1-1/4 (32)
593-8401 1-1/4 (32)
593-8402 1-1/2 (38)
593-8403 1-1/2 (38)
593-8404 1-1/4 (32)
593-8405 1-1/4 (32)
593-8406 1-1/4 (32)
593-8407 1-1/4 (32)
593-8410 1-1/2 (38)
593-8411 1-1/2 (38)
593-8412 1-3/8 (35)
593-8413 1-3/8 (35)
593-8415 1 (25)
593-8416 1 (25)
593-8419 1 (25)
593-8420 1 (25)
593-8421 1-3/8 (35)
593-8422 1-3/8 (35)
593-8423 1-3/8 (35)
594-8343* 1-1/2 (38)
594-8345* 1-1/2 (38)
594-8361* 1-1/2 (38)
594-8363* 1-1/2 (38)
594-8375* 1-1/2 (38)
594-8377* 1-1/2 (38)
Stem
Travel
in. (mm)
* RL 147 is standard with the
product.
Page 7
RL 147 POSITIONING RELAY Technical Instruction
155-038 Page 7
Table 5. Mounting Kit 147-104
for the No. 3 Damper Actuator.
Item Description Q'ty
1 Mounting Bracket 1
2 Feedback Spring (for 2-3/8" stroke) 1
3 Adjusting Screw 1-3/4" (44 mm) long 1
4 Wing Nut 2
5 Lock Washer 1
6 Flat Washer 1
7 Spring Arm 1
8 3/8-24 Hex Nut 1
9 Clevis 1
Figure 6. Positioning Relay Mounted on the
No. 3 Damper Actuator.
#10-16 1/2" (13 mm) Slotted Hex
10
Screw
11 90° Elbow Connector 1
2
Figure 7. Positioning Relay Mounted on the
No. 4 Damper Actuator.
Table 6. Mounting Kit 147-314
for the No. 4 Damper Actuator.
Item Description Q'ty
1 Mounting Bracket 1
2 Feedback Spring 1
3 Adjusting Screw 1-3/4" (44 mm) long 1
4 Wing Nut 2
5 Lock Washer 1
6 Flat Washer 1
7 Spring Arm 1
8 3/8-24 Hex Nut 2
9 Clevis 1
#10-16 1/2" (13 mm) Slotted Hex
10
Screw
1
Page 8
Technical Instruction Landis & Gyr, Inc.
RL 147-2 Page 8
Figure 8. Positioning Relay Mounted
on the No. 6 Damper Actuator.
Table 7. Spring Selection for Adjustable Stroke
of the No. 6 Damper Actuator.
Actuator
Stroke
3-1/4 to 4
(82 to 102)
2-29/32 to
3-1/4
(74 to 82)
Item Description Q'ty
1 Mounting Bracket 1
2
3
4 Wing Nut 2
5 Lock Washer 1
6 Flat Washer 1
7 Spring Arm 1
8 3/8-24 Hex Nut 2
9 90° Elbow Connector 1
Feedback Spring
Color Nominal Max
Blue 4 (102)
Cadmium 3 (76) 3-1/4
Table 8. Mounting Kit 147-276
for the No. 6 Damper Actuator.
Feedback Spring
4" (102 mm) stroke (blue)
Feedback Spring
3" (76 mm) stroke (Cad.)
Adjusting Screw
4-1/2" (114 mm) long
Adjusting Screw
1-3/4" (44 mm) long
4-1/4
(108)
(82)
Adjusting
Screw
4-1/2 (114)
long
1-3/4 (44)
long
1
1
1
1
Figure 9. Positioning Relay Mounted on a
VP 591 8" Valve Actuator.
Table 9. Mounting Kit 147-333
for the VP 591 8" Valve Actuator.
Item Description Q'ty
Feedback Spring-Small Cad. Plate 2
Feedback Spring-Small Red 1
2
Feedback Spring-Large Green 1
Feedback Spring-Small Green 2
3 Adjusting Screw-4" (102 mm) long 1
4 Wing Nut 2
5 Lock Washer 1
6 Flat Washer 1
7 Spring Arm 2
9 90° Elbow Connector 1
Page 9
RL 147 POSITIONING RELAY Technical Instruction
155-038 Page 9
1
LEVER
ASSEMBLY
POSITIONING
RELAY
2
3
4
7
4
1
LEVER
ASSEMBLY
POSITIONING
RELAY
2
3
7
RL0088.R1
Figure 10. Positioning Relay Mounted on a
Flowrite 599 Series 8" Valve Actuator.
9
4
4
9
FEEDBACK
ARM
SPRING
GUIDE
JAM
NUT
STEM
NUT
FEEDBACK
SPRING
ARM
GUIDE
JAM
NUT
STEM
NUT
Table 10. Kit 599-00426 for the Flowrite Series 599
8" Valve Actuator.
Item Description Q'ty
RL 147 Positioning Relay 1
1 Mounting Bracket 1
2 Feedback Spring 1
3 Adjusting Screw 1
4 Wing Nut 2
7 Spring Arm 1
9 90° Elbow Connector 1
Table 11. Kit 599-00423 for the Flowrite Series 599
12" Valve Actuator.
Item Description Q'ty
RL 147 Positioning Relay 1
1 Mounting Bracket 1
2 Feedback Spring 2
3 Adjusting Screw 1
4 Wing Nut 2
7 Spring Arm 1
9 90° Elbow Connector 1
RL0091.R1
Figure 11. Positioning Relay Mounted on a
Flowrite Series 599 12" Valve Actuator.
Page 10
Technical Instruction Landis & Gyr, Inc.
RL 147-2 Page 10
Table 13. Mounting Kit for Super Flowrite and 12"
Flowrite before March 1978. Refer to Figure 12.
Item Description Q'ty
1 Mounting Bracket 1
Feedback Spring-Small Cad. Plate 2
2 Feedback Spring-Small Red 2
Feedback Spring-Large Green 1
3 Adjusting Screw-4-1/2" (114 mm)
long
4 Wing Nut 2
5 Lock Washer 1
6 Flat Washer 1
7 Spring Arm 1
8 Sure-Tite Clamp 1
9 90° Elbow Connector 1
1
Figure 12. Positioning Relay Mounted on the
Flowrite 8" Actuator (Models 1 & 2) and Super Flowrite.
Table 12. Mounting Kit 147-277*
for Flowrite 8” Valve Actuator (Models 1 & 2)
Item Description Q'ty
1 Mounting Bracket 1
Feedback Spring-Small Cad. Plate 2
2 Feedback Spring-Small Red 1
Feedback Spring-Large Green 1
Feedback Spring-Small Green 2
3 Adjusting Screw-4-1/2" (114 mm)
long
4 Wing Nut 2
5 Lock Washer 1
6 Flat Washer 1
7 Spring Arm 1
8 Sure-tite Clamp 1
9 90° Elbow Connector 1
*Also order spring arm # 147-307 for use with
VF 5915” and 6” balanced valves.
1
Page 11
RL 147 POSITIONING RELAY Technical Instruction
155-038 Page 11
Table 14. Mounting Kit 147-311 for the VP 591/3
Flowrite Valve Actuator.
Item Description Q'ty
1 Mounting Bracket 1
Feedback Spring-Small Cad. Plate 2
2 Feedback Spring-Small Red 2
Feedback Spring-Large Green 2
3 Adjusting Screw-6-1/2" (165 mm)
1
long
4 Wing Nut 2
5 Lock Washer 1
6 Flat Washer 1
7 Spring Arm 1
8 5/16-18 x 1/2 long Cap Screw 2
9 90° Elbow Connector 1
Figure 13. Positioning Relay Mounted on a
VF 591/3 Flowrite Valve Actuator.
Figure 14. Dimensions in inches (millimeters).
Information in this publication is based on current specifications. The company reserves the right to make changes
in specifications and models as design improvements are introduced.
Landis & Gyr, Inc.
Copyright © 1996 by Landis & Gyr, Inc. • Printed in the U. S. A.
• 1000 Deerfield Parkway, Buffalo Grove, Illinois 60089
Loading...