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How do I program an I/A Series MNL or MNB controller to read the setpoint of the ETR803 sensor?

Issue

The specification data sheet for the ETR803 sensor shows a supply voltage connection and controller input connection but does not provide any further details for reading the setpoint.

Environment

ETR803 temperature sensor with setpoint

Cause

ETR803 is being used for space temperature sensing and needs to be able to read the setpoint in an I/A Series controller.

Resolution

The ETR803 Space Temperature Sensor with setpoint adjuster is marketed as an equivalent for the TS-90250-850 and similar device.

The space temperature sensor is a 10kohm type 3 thermistor with an 11kohm shunt resistor.  This space temperature sensor can be read by any of the I/A Series controllers that support the 10k thermistor with 11k shunt resistor.

The setpoint adjuster is an uncalibrated Cool / Warm slider that be read by the I/A series controller as a voltage input.

Note: Unlike other ETR sensors, voltage detailed below must be applied to the ETR803 setpoint (SP+ and common) for proper operation.

The power source can be the 5.1VDC power from the MNL-800 or the 20VDC source, with a 4500 ohm series resistor, from the MNB-1000.
For the other controllers, an AO can be configured as a 5 VDC output.  This voltage source is connected to the SP+ terminal on the ETR803.

The SPST output of the ETR803 is then connected to a spare analog input on the controller.
This analog input is configured to read a voltage in the range of 1.2 to 4.8 volts.

Since the ETR803 setpoint slider is uncalibrated, being labeled "Cool" on the left and "Warm" on the right, the AO reading this value could be configured to read an absolute temperature range such as 50 to 90 degrees or could be configured as a +/- setpoint offset.

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Last update:
‎2018-09-06 09:37 AM
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