200kW ventilator-start

[kontajner]

Hi,

I need some suggestion about how to start 200kW ventilator (400/690V 2 pol or 4 pol)?

I have two ventilators. Ventilator 1 is 200kW and for continuously, when ventilator 1 goes down(defect), ventilator 2 has to start automatically. What is best solution for start so big fans and how to switch automatically if the fan 1 defect.
Switche has to be quickly as possible.

thank you!

 

[petronila]

Hello kontajner

If the power source is enought I will start each one DOL.Then
You could install air sensors(Air pressure) in each duct of each ventilator(Fan) to detect if is or not in operation in order to command the backup fan starting. Also you can analize the option of use VFD to obtain energy savings, in this case you can connect the contacts and signals from one VFD1 to give advise to the other VFD2 to operate in case of failure or accidental disconnection.

Regards

Carlos

 

[itsmoked]

Perhaps soft starters, air flow sensors, and a smart relay.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[waross]

Years ago I encountered differential pressure switches being used to prove air flow. This was a combustion code requirement. Add high humidity and the result was no end of problems. The AHJ accepted a rotation sensor on the fan shaft to prove air flow and a world of problems and issues disappeared overnight.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[kontajner]

DOL is not a option.

Soft starter, star-delta or frequency inverter?

 

[waross]

If DOL is not an option for any technical reason you may be best to avoid star-delta also.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[ScottyUK]

Given the limitations you are imposing a VFD is probably your only option if you need to be up to speed 'as quickly as possible', although that is a rather subjective value - what is the maximum tolerable time for changeover?


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If we learn from our mistakes I'm getting a great education!

 

[itsmoked]

I'm now on the VFD bandwagon too. It would, as mentioned, allow some energy saving too if less than full speed scenarios exist.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[kontajner]

what is the maximum tolerable time for changeover?

I don't look time as time. It has to be safety when changeover is made. Fan 1 has to stop and then fan 2 start. If is that 10 min it will be 10min if 30min it will be 30min.

I look for VFD from Danfoss FC302.

 

[ScottyUK]

If you afford 10 minutes for changeover then a soft start would likely be a cheaper solution than a VFD, assuming your source can deliver sufficient power for a soft start to operate properly. A VFD can keep line current below normal running current during acceleration, a soft start can only limit it to roughly 2.5x normal running current during acceleration.


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If we learn from our mistakes I'm getting a great education!

 

[LionelHutz]

You are asking questions about designing the whole control and power system for these fans. It really sounds like you need someone with experience to help. This is a tips site, not a complete engineered solution site.