As a commonly used ventilation and drafting equipment, centrifugal fans need to have some necessary safety protection measures, so that they can be used with confidence. The centrifugal fans produced have safety protection for various situations.
The main safety protection measures of centrifugal fans
1. Fan output limit
When the machine current is greater than or equal to 138.7A, the inlet of the primary fan on the side is adjusted to increase the blocking of the baffle, or the current of the fan is greater than or equal to 138.7A, and the inverter of the primary fan on the side is blocked and increased, the output of the fan will be limited.
2. Trip protection
Centrifugal fans are equipped with fan trip protection measures. When the boiler MFT action is encountered; the fan motor bearing temperature is greater than 100°C (one out of two), the delay is 5s; the fan bearing temperature is greater than 100°C (one out of two), the delay time is 5s; the fan motor When the winding temperature is greater than 130°C (both temperatures in the same phase are high), and the delay is 5s, the fan will trip for protection.
3. Fan outlet cold air door
(1) The cold air door at the outlet of the fan is automatically opened: the fan is running, the circuit breaker is closed, the delay is 30s, and the sequence control command.
(2) The cold air door at the outlet of the fan automatically closes: the fan stops, the circuit breaker opens, and the sequence control command.
(3) The cooling air door at the outlet of the fan is allowed to close: the fan is not running, and the closing position of the circuit breaker is negated.
4. Fan outlet door
(1) The fan outlet door automatically opens: the fan is running, the circuit breaker is closed, the delay is 10s, and the sequence control command.
(2) The outlet door of the fan is automatically closed: the fan stops, the inverter operation signal is not in line with the power frequency opening position or the circuit breaker opening position, and the sequence control command.
(3) The closing of the fan outlet door is allowed: the fan is not running, and the closing position of the circuit breaker is negated.
5. Fan frequency conversion contactor
When the fan power frequency contactor is in the opening position, the fan inverter is reversed due to a serious fault, the fan inverter is remotely controlled, and the fan has no trip condition, it is allowed to close.
6. Fan power frequency contactor
When the fan circuit breaker is at the closing position or the fan variable frequency contactor is at the opening position, it is allowed to close.
After the above introduction, it can be seen that the safety protection measures for centrifugal fans include fan output limit, trip protection, fan outlet cold air door, fan outlet door, fan variable frequency contactor, fan power frequency contactor, etc., in different situations, there are different protective measures, so that everyone can use it with confidence.