Siemens Powers ET 134 Series Owner's manual

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Technical Instructions
Document No. 155-016P25
ET 134-22
Rev. 1, February, 2000
Low Temperature Detection
Thermostat
Siemens Building Technologies, Inc.
Description The electric Low Temperature Detection Cut-out and Alarm Thermostat is a remote bulb
instrument which opens an electrical circuit to stop the supply fan motor and/or closes an
outside air damper when the temperature at the sensing element falls below the setting
of the instrument. Simultaneously, it closes a circuit to indicate an alarm condition.
Features •Manual reset
•Easy temperature setting with adjusting screw on top of enclosure
•Mounting bracket and two screws included
•Main and separate reverse-acting auxiliary contacts
Product Number 134-1504
Warning/Caution Notations
WARNING Personal injury/loss of life may occur if a procedure is
not performed as specified.
CAUTION Equipment damage, or loss of data may occur if the
user does not follow a procedure as specified.
Application This instrument should only be used on those applications where the ambient
temperature to which the instrument case and bellows are exposed remains above
the temperature setting of the thermostat. This thermostat should be used in areas
protected from the weather.

Technical Instructions Low Temperature Detection Cut-out and Alarm Thermostat
Document Number 155-016P25
Rev.1, February, 2000
Page 2 Siemens Building Technologies, Inc.
WARNING:
This low temperature detection thermostat is designed for use
only as an operating control. Where an operating control failure
would result in personal injury and/or loss of property, it is the
installer’s responsibility to add devices (safety, limit controls) or
systems (alarm, supervisory systems) that protect against, or
warn of control failure.
Specifications Switch Action Main (LINE-M2) contacts open on
temperature drop, simultaneously auxiliary
contacts close
Range 15 to 55°F (-9 to 13°C)
Maximum bulb temperature 400°F (204°C)
Minimum differential 5°F (2.8°C) Non-adjustable
Sensing element Vapor filled
Bulb length 1/8-inch OD x 20 feet (6 m)
Reset action Manual
Electrical rating See
Table 1
Weight 2.4 lbs. (1.1 kg)
Dimensions See
Figures 2 and 5
Approvals UL file SA 3863
CSA file LR948
Operation This thermostat incorporates a temperature sensing element of the vapor-filled type
which actuates a heavy duty contact through a rugged link mechanism.
Any one-foot length of the element subjected to temperatures below the temperature
setting of the thermostat will actuate the thermostat switch mechanism regardless of
the temperature being sensedby the remainder of the element. This makes the
thermostats ideal for protecting large coils where air stratification could cause
freezing conditions in a localized area.
The thermostat has a main and auxiliary contact unit. The main load circuit
(LINE-M2) opens on temperature drop and simultaneously, an auxiliary or alarm
circuit (LINE-Ml) closes on temperature drop.
NOTE: The reset button must be manually pressed down and released to resume
normal fan system operation.

Low Temperature Detection Cut-out and Alarm Thermostat Technical Instructions
Document Number 155-016P25
Rev. 1, February, 2000
Siemens Building Technologies, Inc. Page 3
Electrical Ratings
Table 1.
Pole
Number Line-M2 (Main) Line-M1 (Auxiliary)
Motor
Rating 120 V 208 V 240 V 277 V 120 V 208 V 240 V 277 V
AC Full Load
Amps 16.0 9.2 8.0 6.0 3.3 3.0 
AC Locked
Rotor Amps 96.0 55.2 48.0 36.0 19.8 18.0 
AC Non-Ind
Amps 16.0 9.2 8.0 7.2 6.0 6.0 6.0 6.0
Pilot Duty-Both Poles 125 VA, 24 to 600 Vac
57.5 VA, 120 to 300 Vdc
Mounting and
Installation
General Guidelines •Locate the sensing element in the downstream side of the coil.
•Locate the case and bellows where the ambient temperature is always warmer than
the set point.
•Install the thermostat so that the reset button is readily accessible and the element
bellows points down.
•Install as much of the bulb as possible in a horizontal plane. If too much of the bulb is
vertical, it will not operate properly.
•Avoid sharp bends or kinks in the sensing element.
Large walk-in Ducts
(Figure 1)
1. Attach the mounting bracket to the thermostat with the two round head screws
provided.
2. Mount the two perforated steel strap hangers inside the duct with the wide part of the
hanger strap parallel to the air flow.
3. Drill a hole in the side of the duct. With the bulb still coiled, thread the bulb through
the hole using a rotary movement.
4. Mount the thermostat on the outside of the duct.
5. Carefully uncoil the bulb avoiding sharp bends or kinks in the sensing element.
6. Mount the bulb in a horizontal, serpentine manner, attaching the bulb to the strap as
shown in detail in
Figure 1
.
The installation is complete.
NOTE: For an alternate method of mounting, use coil clips (Part Number 356-115) in
the fins to hold the bulb in a horizontal, serpentine pattern.

Technical Instructions Low Temperature Detection Cut-out and Alarm Thermostat
Document Number 155-016P25
Rev.1, February, 2000
Page 4 Siemens Building Technologies, Inc.
Mounting and
Installation, Continued
Figure 1. Typical Mounting in Walk-in Duct.
Limited Access Ducts
(
Figure 2
)1. Attach the mounting bracket to the thermostat with the two round head screws
provided.
2. Attach a mounting flange (part number 808-412) on the opposite side of the duct
(near the bottom) from where the thermostat will be mounted.
3. Mount a second flange on a 8-inch by 4-inch sheet metal plate. Cut an access
opening for the bulb on the duct diagonally across from the duct-mounted flange.
Drill mounting screw holes for the sheet metal plate.
4. Cut a length of copper tubing to fit diagonally across the duct. Stretch out the
bulb and wrap it around the tubing. See
Figure 2.
5. Insert the tubing and bulb through the access hole and into the duct-mounted
flange. Fasten the 8-inch by 4-inch sheet metal plate to the duct.
6. Mount the thermostat on the outside of duct.

Low Temperature Detection Cut-out and Alarm Thermostat Technical Instructions
Document Number 155-016P25
Rev. 1, February, 2000
Siemens Building Technologies, Inc. Page 5
Figure 2. Bulb Mounting for Limited Access Ducts with 808-412 Mounting Flange.
Wiring WARNING:
Disconnect the power supply before wiring connections are made to
avoid possible electrical shock or damage to the equipment.
Make all wiring connections using copper conductors only and in accordance with the
National Electrical Code and local regulations. Loads exceeding the rating of the
thermostat should be handled by means of a relay or motor starter.
An opening for 1/2-inch conduit is provided in the bottom of the thermostat enclosure.
See
Figure 3
for a typical wiring diagram.
Figure 3. Typical Wiring Diagram.
CAUTION:
Use terminal screws furnished (#8-32 x 1/4-inch binder head screw).
Longer terminal screws can interfere with switch mechanism and
damage the switch.

Technical Instructions Low Temperature Detection Cut-out and Alarm Thermostat
Document Number 155-016P25
Rev.1, February, 2000
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. Powers is a trademark of Siemens Building Technologies, Inc. ©2000 Siemens Building Technologies, Inc.
Siemens Building Technologies, Inc.
Landis &Staefa Division
1000 Deerfield Parkway
Buffalo Grove, IL 60089-4513
U.S.A.
Document No. 155-016P25
PrintedintheU.S.A.
Page 6
Adjustment After mounting the thermostat, adjust the temperature setting using the set point
adjusting screw on the top of the enclosure. See
Figure 4.
Observe a complete operatingcycle to be sure that all components function correctly.
Figure 4. Set Point Adjustment Screw.
Calibration There is no field calibration required for the thermostat.
Troubleshooting Observe a complete operatingcycle to be sure that all components function correctly.
Service There is no servicing of the thermostat. Replace if inoperative.
Dimensions
Figure 5. Dimensions in Inches (Millimeters).