Air Conditioning Units Duty Share with Auto Dialler

Sarum manufactures and supplies bespoke control panels to suit your individual requirements and specifications. Our HVAC system engineers work with specifications from consultants in a broad range of building types and industries and our control panels can be made to fit multiple air conditioning units.

Example of a Sarum Electronics Air Conditioning Units Duty Share with Auto Dialler control panel:

This panel was created to control two air conditioning units on a duty share basis with a high condensate alarm for each system.

The panel is designed to run the air conditioning units for a duty period before switching to the second unit. The duty period can be adjusted from 5 hours to 10 days. If the room temperature reaches the first pre-set point on the digital stat then the second unit will be enabled thus allowing both units to run simultaneously. If the temperature continues to rise and reach the second pre-set point, the alarm lamp illuminates, the alarm sounds –although this can be muted – and the optional auto dialler sends a message to the pre-programmed number(s).

The GSM auto dialler sends a text message to up to 5 pre-programmed numbers. An email dialler option is also available. The Sarum control panel has the ability to monitor fault contacts on each unit. If the duty unit goes into a fault condition, that unit’s fault lamp illuminates, the alarm sounds and a message will be sent from the auto dialler. When a fault is detected, the standby unit will be switched on. The condensate alarm works in a similar way.

The air conditioning controller was designed to be linked with the building’s fire alarm system so that when the alarm is activated, the panel automatically shut the systems down.

All control panels are supplied with a circuit diagram attached to the inside of the panel door, along with a circuit diagram and o & m manual provided loose inside the panel.



  1. GSM autodialler with integral battery backup.
  2. Power supply for GSM dialler.
  3. Customer connection terminals, clearly marked with individual terminal markers, with high and low voltage segregated for safety precautions.
  4. Digital thermostat for high-temperature alarm.
  5. Duty cycle timer, adjustable from 5 hours to 10 days.
  6. Door interlocking isolator, to prevent anyone from opening the control panel whilst it is still live.
  7. Audible alarm with mute switch and alarm test button.

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