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colinr avatar image
colinr asked

220A Battery Protect Issues

21161271-090d-462e-bdfa-05726ec6c790.jpegHi All,


I am building a small off grid system for poultry coops that I am building. I have a 220A Battery Protect for the 24v side of the system. The main output on the 24v side is to a 3kW hydraulic motor. To check the system worked I simplified the setup to check the BP worked. I have a positive battery cable going to a bust bar and then another cable going from the bus bar to the IN terminal on the BP and the OUT terminal goes to a fuse which continues on to the 3kw hydraulic motor. The BP negative is connected to a negative bus bar which is connected to the negative on the battery via the negative terminal on the hydraulic motor as it is on the cabling route to the battery. When I try to operate the pump the contactors start clicking like it would on a starter motor of a car with a low battery and the BP give off an electrical burning smell. The system works fine if I bypass the BP. I have two BP's as I'm build two systems

and I connected the other one to check if it was just a faulty BP. Initially I just connected it up the same way but didn't have it attached to the IP box where all the equipment is mounted. Initially I just heard the contractor click once but then ot seemed to work after a few attempts and continued to work thereafter. The next day I mounted it into the box thinking the problem was solved and when I connected the power the same thing happened as the first one so I don't know if there is an earthing issue within the box or something? The box is mounted to a chassis where the plate that everything is mounted to is technically grounded to the chassis through the bolts that hold the cabinet to the wall. Everything within the box runs back to a negative bus bar within the box that is connected to the negative terminal on the battery via the hydraulic motor negative terminal.


I am not an experienced person when it comes to electrics and would appreciate any help in diagnosis the issue.


I have attached a picture showing the setup when testing.


Thanks in Advance


Colin



Battery Protect
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1 Answer
klim8skeptic avatar image
klim8skeptic answered ·

@colinr The BP negative is connected to a negative bus bar which is connected to the negative on the battery via the negative terminal on the hydraulic motor as it is on the cabling route to the battery.

Confirm where the negative bus is connected.

Battery negative??

Or as text suggests, the pump negative terminal (that is then connected to battery) ??

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colinr avatar image colinr commented ·
@klim8skeptic the bus bar is connected to the hydraulic motor negative terminal (which is then connected to the battery negative)
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klim8skeptic avatar image klim8skeptic ♦ colinr commented ·
@colinr sounds like when the pump starts up the current spike is causing a voltage rise between the battery neg and the pump neg. Could be causing the BP to switch states.

Run a separate neg wire from the battery to the BP to test this.


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colinr avatar image colinr klim8skeptic ♦ commented ·
@klim8skeptic we separated the negatives so that each runs back to the battery on their own but it still does the same thing. Bearing in mind I tested the second one I have which was causing the contactor to click once the first few times I tried it on the 3/4 attempt it worked and continued to work after that until I mounted it into the box which is metal backed and earthed. Once mounted it did the same as the other one and wouldn't work whether it was mounted or not to the backplate. I have also now tried a 65amp BP I have and the contactor is clicking on the switch of the motor but it is not running. The BP digital display flashes when you try to run the motor as well. No error codes flash it's just the same flash you get when you first put power to it.


Thanks

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klim8skeptic avatar image klim8skeptic ♦ colinr commented ·
@colinr other than suspecting the battery voltage drops below the BP low voltage cut out when the pump engages, no further ideas.
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