TESTING & TECHNICAL DATA

Fan/Motor Compatibility: The Nimbus-HP is compatible with many PSC (Permanent Split Capacitor) and shaded pole motors. The Nimbus-HP is not compatible with capacitor start motors. Confirm TRIAC controllability with the motor manufacturer before installation or contact CRI customer service for testing recommendations. Attempting to control a motor that is not compatible could cause excessive heating and could permanently damage the motor.

Control Accuracy and Hysteresis: The standard Nimbus-HP is accurate to within ±1.5°C in the temperature control mode and ±0.4VDC, ±0.8mA in the control signal mode. If your application requires greater accuracy, contact customer service. For most singlephase AC fans, there is direct correlation between speed and voltage. For some fans however, this will not be the case. To prevent fans (using fan ON/OFF feature) and alarms from cycling on and off, a certain amount of hysteresis has been built in to the Nimbus-HP. That is, fans will shut off 2-3% below the set point and turn back on 2-3% above the set point. Alarms will turn on at the set point and turn off 1-2°C below or 5% above the set point.

Voltage Loss:
For a typical fan, expect a voltage drop to the fan of about 4-10% at full voltage.

Power connections are made through ¼” x .032” spade lugs (TB3, TB4) located on the circuit board. Use insulated quick connects to connect to the spade lugs. When installing Nimbus-HP with the enclosure, connect fan and power wires through the 0.813” D hole in the side of enclosure and secure with a strain relief.

The Nimbus HP is not compatible with Uninterruptible Power Supplies (UPS) that generate a square wave.

Changing Control Settings:
With the exception of the “fixed speed mode”, the Nimbus-HP will not recognize any changes in switch or jumper settings made with power applied. Power must be turned OFF before changing any switch or jumper settings.