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Posted By Topic: cow shed

acltd
Aug 17 2016 15:33

Are there any common problems to look for in a cow shed if the cows don't like one side of the rail. I have not been to the job yet but the farmer explains it that the cows don't like the right side of his shed. I did ask if anything has changed and he said its the same side as that the milk pump vsd is mounted on which was done a little while ago but the cows also get rattled when the wash down pump is flicked on.
   

AlecK
Aug 17 2016 16:14

There's an entire handbook available from SNZ on cowsheds(HB 6117; $85.50).

It doesn't take much touch voltage to upset cows; and you need to follow very good earthing & bonding practices, including ensuring ow impedance to HF currents
You'l also need an oscilliscope rather ythan a normal volmetert designed for 50 Hz
   

ShaneR
Aug 17 2016 18:02

I spent may weeks finding a similar problem.

The problem was it would come a go and seamed to to get worse when it rained but not always.

Impedance meter is your friend.

assuming 3 phase supply

At the main switch Check

L1 - N
L2 - N
L3 - N

L1 - L2
L2 - L3
L1 - L3

Assuming the cable size are all the same you should get similar reading.

I was getting a high reading on the neutral cable (6 Ohms from memory) took me ages to find a bad connection join in the cable.

There is a AS/NZS standard that has a test procedure in it for testing neutrals, can remember the number








   

ShaneR
Aug 17 2016 18:26

AS/NZS 3017:2007
Electrical installations - Verification guidelines

https://shop.standards.govt.nz/catalog/3017%3A2007%28AS%7CNZS%29/view
   

Wairewa
Sep 19 2016 11:20

Is there anyone providing straight out testing for dairy sheds? An independent report would be beneficial.
   

ShaneR
Sep 19 2016 11:39

"Is there anyone providing straight out testing for dairy sheds? An independent report would be beneficial."




Can you explain more?
   

Sarmajor
Sep 19 2016 19:02

Corkill systems offer a service for hunting down stray voltages in dairy sheds.


   

Wairewa
Sep 21 2016 10:43

Thanks Sarmajor. Looks like Advanced Dairy do it too. Bit closer to home. Cheers.