Siemens 6RA70 Alarm Description A025 Brush length too short, A027 Air flow monitoring

Alarm	Description
No.

A025	Brush length too short
	(active in all operating states)
	When parameter P495=1 (binary sensing of brush length):
	Alarm in response to log. “0” signal (longer than 10s) at terminal 211

Possible causes

♦Encoder for brush length has responded

♦Interruption in encoder cable

A026 Poor bearing condition (active in all operating states)

When parameter P496=1 (bearing condition sensing):

Alarm in response to log. “0” signal (longer than 2s) at terminal 212

Possible causes

♦Encoder for bearing condition has responded

A027 Air flow monitoring

(active in operating states of < o6)

When parameter P497=1 (air flow monitoring):

Alarm in response to log. “0” signal (longer than 40s) at terminal 213

Possible causes

♦Encoder for fan monitoring has responded

♦Interruption in encoder cable

A028 Motor overtemperature (active in all operating states)

When parameter P498=1 (thermostat connected):

Alarm in response to log. “0” signal (longer than 10s) at terminal 214

Possible causes

♦Thermostat for monitoring motor temperature has responded

♦Interruption in encoder cable

A029 Motor overtemperature (active in all operating states)

Selection via P493=1 or 3 (thermostat at terminals 22 / 23) or

P494=1 or 3 (thermostat at terminals 204 / 205)

When parameter P490.01=1 (KTY84 at terminals 22 / 23) or P490.02=1 (KTY84 at terminals 204 / 205):

The alarm is activated if the motor temperature reaches or exceeds the values set in parameter P492.

When parameter P490.01=2, 3, 4 or 5 (PTC thermistor at terminals 22 / 23) or P490.02=2, 3, 4 or 5 (PTC thermistor at terminals

204 / 205):

The alarm is activated if the motor temperature reaches or exceeds the trip value of the selected PTC.

A030 Commutation failure or overcurrent has occurred

(active in operating states of – –, I, II)

Possible error causes

♦Mains voltage dip in regenerative feedback mode

♦Current control loop not optimized

A031 Speed controller monitoring (active in operating states of – –, I, II)

The monitor responds when the difference between the connectors selected in P590 and P591 (factory setting: Setpoint/actual value difference of speed controller) exceeds the limit set in parameter P388 for longer than the time set in parameter P390.

Possible causes

♦Control loop interrupted

♦Controller is not optimized

♦P590 or P591 is not correctly parameterized

Siemens Energy & Automation	9-29
SIMOREG DC Master Base Drive Panel	Operating Instructions