Application Note: Condensate Pan Overflow Switch

Problem / Opportunity:

Condensate overflow switches are common throughout installations of Heat Pumps and other DX Cooling equipment when placed above a ceiling, or in other areas where a leak could be detrimental.  These switches will be interlocked in some way with the unit controls so that the unit shuts down when high liquid level is sensed in the pan.  There are multiple problems this creates:

1. Once the unit shuts down, the condensate pan will slowly drain since the drain is rarely completely plugged on the first instance.  This creates unnecessary cycling of the unit without any awareness to facility staff and confusion over the intermittent failure root cause.

2. Condensate overflow switch trips are frequently confused with other issues, such as failed thermostats, failed mechanical cooling, and faulty transformers.  The result is wasted time and cost by causing multiple callbacks to the same unit and potentially wasted parts.

3. There is no remote visibility of the status of these switches.

Solution:

Using a HyperStat, the condensate pan overflow switch may be removed from the control circuit and placed directly on an input.  Using the Door/Window sensor function on the HyperStat, the switch should be wired to TH2, AI1 or AI2 on the HyperStat backboard.  An alert then can be created to notify all essential personnel of a high condensate level condition.

Result:

• The condensate pan overflow switch is removed from the control circuit but will continue to shut the unit down when a high condensate level condition occurs.  This leads to an easier troubleshooting process.
• Data on when the condition occurred will be tracked in Facilisight, allowing Facility staff and/or technicians to be aware of the problem before arriving for troubleshooting.
• Alerts will result in faster response by critical staff, resulting in lessened discomfort by the occupants in the space, and potential prevention of water damage.

Example of what this condition will look like in Facilisight:

Notes:

• For alert configuration, contact 75F Support at support@75f.io or 888-612-7575.
• The condensate pan overflow switch must OPEN when liquid is detected.
• If using AI1 or AI2 as the input, you must add a jumper on the AI1 or AI2 terminal connectors on the HyperStat backboard.  Jumpers are in Position 4 in the image below:
  
  

For additional information refer to:

HyperStat Overview and Installation

HyperStat Conventional Package Unit (CPU)

HyperStat Heat Pump Unit (HPU)

HyperStat Jumper Settings & Operation