Cooling Fan control (06.045) can be used to select various fan control functions as shown in the table below. The actual control speed of the fan(s) in

given in Cooling Fan Speed (06.046). There are 10 control speeds for the fan(s) in the drive, however the actual hardware control is more coarse than

this, and so there may not be an actual change of fan speed as Cooling Fan Speed (06.046) changes from one value to the next. The default value for

Cooling Fan control (06.045) is 10, which gives maximum cooling and does not limit the fan speed below its maximum. It should be noted that if the speed

is limited, by setting a lower value, then the drive may trip prematurely under load.

Cooling Fan control

Function Selected

(06.045)

Minimum fan noise function with fan speed limited to

-10 to -1

the value of Cooling Fan control (06.045).

Fan does not run.

Maximum cooling with fan speed limited to the

1 to 10

modulus of Cooling Fan control (06.045).

Fan runs continuously at full speed.

The two possible control characteristics are shown in the diagram below.

The fan speed is derived from Percentage Of Drive Thermal Trip Level (07.036) which shows the percentage to the trip level of the hottest monitored point

in the drive. The "Maximum Cooling" characteristic brings the fan(s) on at a relatively low temperature to give maximum cooling. The "Minimum Fan

Noise" characteristic does not switch on the fan(s) until the drive temperature has risen significantly, and the characteristic has a lower gradient. Therefore

with lighter continuous loads the fan noise is kept to a minimum. This characteristic also prevents the fan(s) from coming on when the drive is disabled

and operating in a high ambient. With both characteristics a filter is applied to Percentage Of Drive Thermal Trip Level (07.036) to avoid the fans switching

on and off during short high transient loads. The "Minimum Fan Noise" characteristic also includes a hysteresis band of 15% that is applied to the

percentage of drive thermal trip level at the input to the control algorithm to prevent the feedback from changing the speed back again. This reduces the

chance of the fan repetitively changing speed under constant load conditions.

Parameter

06.046 Cooling Fan Speed

Short description

Cooling Fan Speed

Mode

Open‑Loop

Minimum

Default

Type

8 Bit Volatile

Display Format