Data Sheet for Product

ET 141 Line Voltage Remote Bulb Thermostats Technical Instructions
Document Number 155-019P25
November 1, 2007
Siemens Industry, Inc. Page 5
Wiring Diagrams
All wiring should be done according to the National Electrical Code (NEC) and local
regulations.
This control has an SPDT snap action switch. The bottom terminal (red) is the common
terminal. The middle terminal (blue) has an open-on-rise switch action. The top terminal
(yellow) has a close-on-rise switch action. See Figure 3.
Figure 3. Wiring Diagrams.
Operation and
Adjustment
The setpoint adjustment knob permits adjustment of the setpoint between 100°F and
240°F (38°C and 116°C) for 141-0521, and 30°F to 110°F (-1.1°C to 43°C) for 141-0520.
The temperature differential is adjustable: 3.5°F to 14°F (1.4°C to 7.8°C) for 141-0520,
and 6°F to 24°F (3°C to 13.33°C) for 141-0521.
The standard model includes a knob for setpoint adjustment.
On boiler applications where the control is used as a high temperature operating control,
follow the boiler manufacturer's recommendations for temperature settings.
Temperature Setpoint
Stop
The temperature setpoint stop is an integral part of these controls, and is field adjustable.
To set the stop, do the following:
1. Set dial temperature at desired stop.
2. Remove control cover.
3. Loosen the stop screw, slide the screw to the front of the control against the plastic
stop behind the dial, and tighten the screw (see Figure 2). Sometimes, an exact stop
setting is not possible, and the stop must be set to the closest stop corresponding to
the required dial setting.
Figure 4. Setpoint Stop Screw.
Service
Thermostat is not repairable. Replace if inoperative.