Unicorn 3 Solar Panel...
Hi, Anybody out there with first hand knowledge. Has the solar panel on a Unicorn 3 been fitted with a switch or anything to isolate power from the controller to the battery, I need the info to make a battery swap in a safe spark free manner!... Nothing in Baileys handbook, TIA Shuckford...
Comments
-
On my one there is a fuse under the bed (front end) just before the wiring loom disappears through the floor.
Hope this helps
0 -
If you disconnect the negative first and reconnect it last you won't get a spark.
1 -
Not quite sure how "disconnect the negative first, won't result in a spark".
On a negative earth chassis , you disconnect the negative first to reduce the risk of shorting out the battery terminal to earth with the spanner!
If there is current flowing in the circuit you will get a spark as you disconnect, which either side is disconnected first.
0 -
The spark is produced by the voltage not the current and only occurs if there is enough potential difference to break down the dielectric (air in this case). If both negatives are grounded to the chassis I can't see where the potential difference occurs between negative and chassis. When I jump start a car I have never experienced a spark from the black, negative, lead if connected second but often from the red, positive, lead if connected last. Opposite for disconnection.
Anyway, agree that it is not safe to remove positive first in an active circuit due to the possibility of accidentally touching the grounded chassis.
0 -
I apologise hitchglitch if my post offended, that wasn't my intention.
My referring to current flow was only a way of stating that if there was a closed circuit. A spark wouldn't be produce in a open circuit situation.
I agree that You are totally correct about the pd in the voltage being the cause of a spark and not the current.
Can we agree that wherever a closed circuit is broken, the resulting ends will result in a posstive and negative, even if the break is in fact the disconnection of the negative battery terminal?
0 -
That's OK. I am not easily offended!
0 -
.... and I didn't respond to the comment. Apologies because this is a bit off topic.
If you are foolish enough to disconnect a live, red, terminal from a switch in your home you are quite likely to get a spark. You might also kill yourself if you touch it which, unfortunately, many people do.
If you disconnect the neutral, even in a circuit carrying current, you will not get a spark. In fact, you can grab hold of it without ill effect. Not that I would recommend it (although I have done it myself!). The circuit carries current but the neutral is at earth potential and there is no potential difference to cause an electric shock.
In a car or caravan the negative, black, is earthed to the chassis so you cannot get a spark.
Whatever you do, always isolate the circuit first because apart from the possibility of sparks or shocks, it can cause damage to electronic equipment if you don't isolate it properly before working on it.
Which brings us back to the OPs original question which unfortunately I cannot help with.
0 -
If the OP says which van he has I am sure someone will tell him where the in-line fuse is. On the Madrid it is under the cooker behind the drop down glass flap.
0 -
Unicorn Valencia 3 under the double bed.
0 -
If you disconnect the neutral, even in a circuit carrying current, you will not get a spark. In fact, you can grab hold of it without ill effect. Not that I would recommend it (although I have done it myself!). The circuit carries current but the neutral is at earth potential and there is no potential difference to cause an electric shock.
- I agree with this as it is a ac circuit
Sometimes referred to as line and neutral
In a car or caravan the negative, black, is earthed to the chassis so you cannot get a spark.
- this is a dc circuit ,
Positive and negative
If you disconnect the battery negative on a live (dc) circuit you will get a spark. This part of the reason that you will find fuel tankers and other such specialised vehicles, are insulated return ( no earth ground connection) and have battery master switches that are operated before loading and unloading flammable/ explosive cargos.
I've even just gone out and and just disconnected the negative terminal on my caravan and it sparks everything time the connection is broken and connected!
0 -
I guess I was thinking that the negative remained grounded to the chassis and the line break was elsewhere. Agree that if you break the earth connection you could get a potential difference and I accept what you say (although I have never had a spark). Thanks.
0
