PSB Circuit Board with Pulse Wave Modulator

The dual function pressure sensing circuit board (PSB) makes zoning simple and easy. It eliminates the need for by-pass dampers and dump zones.

The PSB sends control signals to the heating/cooling source. When used with inverter heat pump air conditioning DX outdoor units, it is connected to an interface panel supplied by the heat pump manufacturer.

Two different control methods provide a 0 – 10vdc output signal to the variable frequency drive (VFD):

  1. Automatic Mode
    This is the recommended method of fan speed control and the standard factory setting. It makes zoning simple. A pressure sensor modulates fan speed and makes automatic airflow adjustments to maintain a constant supply air static pressure.
  1. Manual Mode
    This allows for direct speed control of the fan anywhere from 0 – 100% capability, by manually selecting the output value of the WEG inverter drive. It bypasses the pressure sensor used in automatic mode and can be used in single zone applications. It does not compensate for dirty filter or closed outlets.

Ingenious Air Small Duct System PSB Circuit Board

PSB Circuit Board

 Pulse Wave Modulator

A pre-installed pulse wave modulator (PWM) speed controls the EC fan motor via the WEG inverter drive. The PWM measures the pressure in the supply plenum duct versus the ambient air pressure. It then automatically adjusts the fan speed to achieve the pressure set during commissioning. This keeps energy use to a minimum by only moving air when required to where it is required.

Fan speed is individually set for cooling, heating and constant fan. Airflow can easily be adjusted for all modes using the trim pots (COOL, HEAT and FAN).

If a zone damper or outlet is switched off, the pressure will increase in the duct. The PWM will automatically react and slow the fan down.

If the filters get dirty the fan automatically increases speed to maintain the required duct pressure.

Create your perfect indoor climate today:
Call 0800 731 6352 or 01268 544530 or email