Autoformer issue
Can someone with a Hughes Autoformer tell me if it is normal to measure around 10 ohms of resistance between the hot and neutral prongs of the plug? I was expecting infinite resistance, so hoping to ...
Forum Discussion
The Hughes Autoformer I have has triacs that determine which transformer tap is active. As such measuring dc resistance between hot input and the hot output may be something much higher than expected as you are going through a triac.
There will be some resistance between the neutral and hot due to the voltage sensing circuit in the Autoformer.
The neutral lead goes direct from the input to the output so it should measure very low in dc resistance.
When I first received my Autoformer Hughes had reversed the output leads which resulted in the hot lead being on the neutral of the output. Also my trailer was wired wrong in that the ground and neutral had been bonded. This resulted in the trailer frame connected to the hot lead. Thus you will receive a shock if you touch the trailer while standing on the ground outside the trailer.
This can be checked on the Autoformer. As stated above the neutral goes direct through the Autoformer. Thus input neutral to output neutral should be a very low dc resistance. The hot goes through the transformer and because of the triacs there will be some resistance measured between input and output hot leads.
There should be infinate resistance between ground on the Autoformer and either the hot or neutral lead.
I discovered my problem when my Hughes was new and Hughes replaced my Autoformer under warranty.
There will be some resistance between the neutral and hot due to the voltage sensing circuit in the Autoformer.
The neutral lead goes direct from the input to the output so it should measure very low in dc resistance.
When I first received my Autoformer Hughes had reversed the output leads which resulted in the hot lead being on the neutral of the output. Also my trailer was wired wrong in that the ground and neutral had been bonded. This resulted in the trailer frame connected to the hot lead. Thus you will receive a shock if you touch the trailer while standing on the ground outside the trailer.
This can be checked on the Autoformer. As stated above the neutral goes direct through the Autoformer. Thus input neutral to output neutral should be a very low dc resistance. The hot goes through the transformer and because of the triacs there will be some resistance measured between input and output hot leads.
There should be infinate resistance between ground on the Autoformer and either the hot or neutral lead.
I discovered my problem when my Hughes was new and Hughes replaced my Autoformer under warranty.
