Powering a fan

[davedb]

Could you use a impact mole to burrow under the sheds and then push a duct in for your cable?

 

[defender]

To start a 50 hp fan on direct start would need 150 kava genny , soft start would need about 80kva
Cable would be best if possible , Dont just assume that the power is available without checking load that the transformer can provide or you might get a nasty shock from your supplier, fuse sizes will give an indication . If putting in a cable put in 5 core . Is there anything to stop you fastening cable to outside of building up out of harm's way ?
You would need at least 50sq mm cable

 

[Pheasant Surprise]

Cable will be the best, but finding a shorter run if at all possible. Generators are expensive to buy and run relatively. Only use them as a last resort.

If you can optimise (shorten) the cable path and use modern techniques, like soft starters, to reduce the start load current, this reduces the size of the cable you will need. Drops your install costs massively.

 

[Courier]

Engine driven fan?

Or a PTO drive off an older tractor with a good cooling system and maybe a failsafe system added.

Makes a lot of sense if electric supply is limited.

 

[Beefsmith]

So had a second opinion and the smallest generator to start it up would be 3 times the size of the fan, so yes 150kva is slightly to big but not by much. I think we’ll go down the inverter route with a cable.

 

[debe]

Got two engine driven fans here, ones looking for a new home and isnt dear, just very loud!

 

[Brisel]

I've fitted inverters to 2 x 50 hp fans recently after 3 burnouts in 6 months. The last one was due to an undetected damaged contactor in the star delta gear. They still pull 75A each at full chat with a decent back pressure for drying airflow rates.

Tractor powered fans are highly inefficient - really you need to recover as much of the excess heat generated by the tractor as possible which means a shed or scaffolding and a home made marquee. A Murphy switch will protect the tractor and cut the engine if trouble arises. Engine driven fans are nearly as bad. If this is a long term project, hard wire the electric & run inverters to reduce start up power requirements.