Compressor operation - Johnson Controls - LIT-12011950 - Building automation software - Smart Equipment Controller - 5.0

Smart Equipment Controls Sequence of Operation Technical Bulletin

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Smart Equipment Controller
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Technical Bulletin
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This section assumes free cooling is not available.

Compressors are controlled by the Y1 through Y4 thermostat inputs. If the lead/lag function is set to No, a Y1 input energizes the C1 output. The thermostat inputs into Y2 through Y4, energize the C2 through C4 outputs respectively.

Note: If lead/lag function is set to Yes, see Lead/lag compressor equalized runtime for additional information.
Note: Some configurations do not sequence in order. See Unique equipment identifiers.

The FAN output for indoor fan operation energizes with any cooling output after the fan on delay for cool expires.

CN-FAN output energizes when either C1 or C2 is energized in the standard configuration.

CF2 energizes when either C3 or C4 is energized in the standard configuration.

A 30-second interstage delay occurs when multiple stages are requested.

When the thermostat cooling inputs are lost and the minimum runtime expires, the compressor outputs stage off.

Note: A Y2 input without a Y1 input energizes C1 first and then C2 30 seconds later. A Y3 input without a Y1 or a Y2 input energizes C1 first, then C2 and C3 in 30-second intervals. Similarly, a Y4 input without a Y1, a Y2, or a Y3 input, energizes C1 through C4 respectively.