Diagnostics
Programmable Relays (Alarms and Status)
CH530 provides a flexible alarm or chiller status indication to a remote location through a hard wired interface to a dry contact closure.
Four relays are available for this function, and they are provided (generally with a Quad Relay Output LLID) as part of the Alarm Relay Output Option.
The events/states that can be assigned to the programmable relays are listed in the following table and through a TechView configuration.
Table 8 - Chiller events/status descriptions
Event/state | Description |
Alarm - Latching | This output is true whenever there is any active diagnostic that requires a manual reset to clear, that affects the chiller, the |
| circuit, or any of the compressors on a circuit. This classification does not include informational diagnostics. |
|
|
Alarm - Auto reset | This output is true whenever there is any active diagnostic that could automatically clear that affects the chiller, the circuit or |
| any of the compressors on a circuit. This classification does not include informational diagnostics. If all of the auto resetting |
| diagnostics were to clear, this output would return to a false condition. |
|
|
Alarm | This output is true whenever there is any diagnostic affecting any component, whether latching or automatically clearing. This |
| classification does not include informational diagnostics. |
|
|
Warning | This output is true whenever there is any informational diagnostic affecting any component, whether latching or automatically |
| clearing. |
|
|
Chiller Limit Mode | This output is true whenever the chiller has been running in one of the Unloading types of limit modes (Condenser, |
| Evaporator, Current Limit or Phase Imbalance Limit) continuously for the last 20 minutes. A given limit or overlapping of |
| different limits must be in effect continuously for 20 minutes prior to the output becoming true. It will become false, if no |
| Unload limits are present for 1 minute. The filter prevents short duration or transient repetitive limits from indicating. The |
| chiller is considered to be in a limit mode for the purposes of front panel display and annunciation, on if it is fully inhibiting |
| loading by virtue of being in either the "hold" or "forced unload" regions of the limit control, excluding the "limited loading |
| region". In previous designs, the "limit load" region of the limit control was included in the criteria for the limit mode call out |
| on the front panel and annunciation outputs. |
Compressor Running | The output is true whenever any compressors are started or running on the chiller and false when no compressors are either |
| starting or running on the chiller. This status may or may not reflect the true status of the compressor in Service Pumpdown |
| if such a mode exists for a particular chiller. |
|
|
Maximum Capacity | The output is true whenever the chiller has reached maximum capacity continuously for the Max Capacity Relay debounce |
| time. The output is false when the chiller does not have all its available compressors running continuously for the debounce |
| time. |
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|
Table 9 - Default settings
Default setting | Event/Status |
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|
Output relay 1 | Compressor running |
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|
Output relay 2 | Latching alarm |
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Output relay 3 | Chiller limit mode |
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Output relay 4 | Warnings |
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