Is it normal for the Isolation transformer to hum?

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victorvanwaveren asked Jan 8, '19

Is it normal for the Isolation transformer to hum?

Hallo

My iso trans 3600w auto is humming. Is this normal? Than if i measure between input output earth i measure connection. This should not be possible is it? Between in and out neatral not conection measured, also not between live in and out.

Now if i disconnect the land powercable, no connection between earth in and out is measured.

When i measure the earth in the plug from landpower cable, connected on shore, DISconnected on ship, is measured connection between ship and earth from cable, so shore earth.

Is this normal? Do i have a good protection against corrosion?

Isolation Tranformer

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Modifications Space

Node Red Space

Answer 1 · 2019-01-08T12:19:37Z

boekel answered · Jan 08, 2019 at 12:19 PM

Sounds ok. Did you try to measure DC voltage between those two? resistance is not the way to measure when in use.

If you want to know if your hull is protected, there is a way of measuring:

hang a copper wire with the end stripped bare (10cm?) beside the boat, than measure with a (milli)voltmeter between hull and wire (positive connection on wire). (it can take a bit to stabilize)

for a steel hull:

1) > 650 mV protected (by anodes or other system)
2) ca 650 mV unprotected
3) < 650 mV actively corroding

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Answer 2 · 2019-01-08T12:51:28Z

robbo answered · Jan 08, 2019 at 12:51 PM

Page 7 of the manual goes into what jumpers for when floating or on shore. Is it correct on yours?
https://www.victronenergy.com/upload/documents/Manual-Isolation-transformer-2000W-3600W-and-3600W-Auto-EN-NL-FR-DE-ES.pdf

My IT hums a bit, more when loaded.

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Answer 3 · 2019-01-08T14:22:45Z

victorvanwaveren answered · Jan 08, 2019 at 02:22 PM

Hello all,

Thanx for the answers!

@ Robbo, yes its connected as manual

@ Boekel, its hat to be MORE than 650mv to be protected?

And do you mean measuring DC between hull and shore earth in first part of your answer? Thanx in advance!

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