Additional specifications and description
What is the purpose of an HVAC potentiometer?
The control signal (output potentiometer) increases or decreases according to the position of the rotary knob. This control signal can directly control EC fans or damper actuators. It can also remotely control AC fan speed controllers (EVS or MVS series) or frequency inverters (FI-E series). E.g. the potentiometer can be installed in the living room while the fan speed controller is located in a technical room or electrical cabinet.
Adjustable minimum and maximum level
For some applications, it is desirable to adjust the low limit and the high limit of the control signal. Some EC motors or damper actuators cannot handle control signals that are too low. The low limit of the control signal can be adjusted via a built-in trimmer. Sometimes, a fan is overdimensioned. In that case, the high limit of the control signal can be reduced via the maximum trimmer. This will limit the maximum fan speed.
What are the limits of the control signal?
This depends on the MTP-D supply voltage. The supplied voltage must be in the range of 3 - 15 VDC. The minimum value can then be set between 10 and 70 % of the supplied voltage. The maximum value can be set between 30 and 100 % of the supplied voltage. Always check that the applied limits in combination with the supplied voltage result in an output signal that complies with the specifications of the connected device.
E.g. if the supplied voltage is 15 VDC and the high limit is set to 100 %, the connected device must be able to handle a control signal up to 15 VDC.
Without OFF position
In some occasions, it is technically or legally required to ensure a minimum air supply in all circumstances. Since this potentiometer does not have an OFF position, the control signal will never reach 0 V. Even when the rotary knob is at minimum position (turned counter clockwise), the control signal will be at minimum value. This low level can be adjusted via the built-in trimmer.
Dry contact output
The dry contact output can be used to control an external device. When the rotary knob is at minimum position, the contact output is open. When the rotary knob is turned clockwise, the contact will immediately close.