Kobold TWR Operating Manual

KOBOLD Instruments Inc.
1801 Parkway View Drive
Pittsburgh, PA 15205
PH: 412-788-2830
FAX: [phone]
www.koboldusa.com

Series TWR
Temperature Switch

Precautions

• User's Responsibility for Safety: KOBOLD manufactures
a wide range of process sensors and technologies. While
each of these technologies are designed to operate in a
wide variety of applications, it is the user's responsibility to
select a technology that is appropriate for the application,
to install it properly , to perform tests of the installed system,
and to maintain all components. The failure to do so could
result in property damage or serious injury.

• Proper Installation and Handling: Use a proper thread
sealant with all installations. Never overtighten the sensor
within its fitting. Always check for leaks prior to system
start-up.

• Wiring and Electrical: Because this is an electrically
operated device, only properly trained personnel should
install and maintain this product. Review the specifications
for maximum electrical switch ratings. Do not exceed these
ratings. Electrical wiring of the sensor should be performed
in accordance with all applicable national, state and local
codes.

• T emperature and Pressure: The TWR is designed for use
in process temperatures from -30°C to +125°C. Operation
outside these limitations will cause damage to the unit.

Specifications

Accuracy: ±5-7°C (±9-13°F)
Hysteresis: Max. 20°C (36°F)
Wetted Parts: Nickel-plated brass or 1.4301 (304)

SS depending on model

Fitting: 3/4” NPT
Max. Pressure: 64 Bar (928 PSIG)
Temperature Range: -30°C to +125°C (-22°F to +257°F)

• Material Compatibility: The TWR’s process wetted parts
are nickel-plated brass or stainless steel depending on th e
model. Make sure that the TWR is chemically compatible
with the application liquids. While the sensor’s outer
housing is liquid resistant when installed properly, it is not
designed to be immersed. It should be mounted in such a
way that it does not normally come into contact with fluid.

• Flammable, Explosive and Hazardous Applications:

The TWR is considered a simple apparatus per the U.S.
National Electric Code. It can be made intrinsically safe if
properly installed with an intrinsic safety barrier per the
requirements of the National Code.

• Make a Fail-Safe System: Design a fail-safe system that
accommodates the possibility of sensor or power failure.
In critical applications, KOBOLD recommends the use of
redundant backup systems and alarms in addition to the
primary system.

Dimensions

1.38”
PG 9

Electrical Specifications:
Switch Type: SPST normally open (N/O) or

normally closed (N/C) based on
model

Switch Rating

Standard: Max. 250 VAC, 30 VDC, 4 A
Option LED: 24 VDC
Option GLP: 110 VAC

Electrical Connection: DIN 43 650
Electrical Protection: IP 65

2.95”

(3.23” with signal lamp)

1.15”

¾” NPT

All dimensions in inches unless otherwise noted

FM Rev. 4/29/11

TWR_datasheet_man

Order Codes

Con-

tact

Type

N/O TWR-5101 TWR-5201
N/C TWR-5102 TWR-5202

Part Number Options

Brass Stainless Switch status signal lamp

Electrical Connections

(add to part number)

-LED = 24 VDC Lamp

-GLP = 110 VAC Lamp

Switch Point Options in °C (°F)

switchpoint is stamped on TWR body
(add to base p/n as suffix):
30( 86), 35( 95)
40(104), 45(113)
50(122), 60(140)
70(158), 80(176)
90(194), 100(212)
110(230), 120(248)

TWR

TWR

1

2

3

N/O Function

1

2

3

N

L
O
A
D

Line / +VDC

L
O
A
D

Neutral / -VDC

Line / +VDC

Neutral / -VDC

TWR

TWR

1

2

3

N/C Function

1

2

3

N

Line / +VDC

L
O
A
D

Neutral / -VDC

Line / +VDC

L
O
A
D

Neutral / -VDC

N/O Function with Lamp

Note: for versions with signal lamp, the lamp is lit when switch is open

Mechanical Installation

1. Use a proper thread sealant to install the switch in its
fitting

2. Ensure that the sensing bulb is immersed in the liquid
to be monitored. If the switch is installed in an air pocket
slow response or malfunction of the switch will occur.

3. If installing into a horizontal pipe, do not install at the
top (12 O’clock) position on the pipe. Air bubbles which
form in the top of the pipe will insulate the switch sensing
bulb and result in slow operation or switch malfunction.

4. If installing into a horizontal pipe, do not install at the
bottom (6 O’clock) position. Sediments may deposit on the
sensing bulb causing slow response or switch malfunction.

5. Ensure that the coupling used to install the TWR is
short enough to allow the sensing bulb to extend past the
pipe or tank wall and into the liquid to be monitored. If the
switch sensing bulb is recessed into the coupling, a
stagnant liquid pocket will form around the sensing bulb.
The liquid temperature in this stagnant area may not be
representative of the bulk liquid temperature, resulting in
errors or false switching.

N/C Function with Lamp