Rob said:
Yes - I meant don't connect the case to the 240v neutral
Don't like the adverts? Click here to remove them
Inverter fitted
- Thread starter AndyCook
- Start date
Yes - I meant don't connect the case to the 240v neutral
- Joined
- Feb 24, 2010
- Messages
- 6,131
- Country Flag
Re: Re: Inverter fitted
Ground and neutral not the same thing here. Normal house power yes, not her.
Best would be to ground the chassis to the truck and if you really want, a spike into the ground (soil). That would give the RCD a fighting chance to save your life.
Sent from my GT-P7510 using Tapatalk
Rob said:I think the reason why we came to the conclusion to connect neutral, negative and case is because the manual says to ground the case, and the negative terminal on the battery is ground on the car
Ground and neutral not the same thing here. Normal house power yes, not her.
Best would be to ground the chassis to the truck and if you really want, a spike into the ground (soil). That would give the RCD a fighting chance to save your life.
Sent from my GT-P7510 using Tapatalk
- Joined
- Feb 24, 2010
- Messages
- 6,131
- Country Flag
Re: Re: Inverter fitted
I've played with it, not much use. Depending on item, they might not like the lower voltage. Some cf bulbs will not ignite with the lower voltage. The current draw on some things is not enough to allow the inverter to come out of standby. Some motor items might stall?
All modes will drain your batteries after a while (few days). I have the remote switches now which will allow you to put a switch on the dash or make it come on with the ignition. Best way.
When I'm back from sa I'll test and share them.
Sent from my GT-P7510 using Tapatalk
Justin_Elliott said:Forgot to ask - has anyone changed the power mode for their inverter?
According to the manual, the mode can be selected by changing the jumper settings (on PCB behind top cover).
Modes available:
Standard - 230V output voltage
Low Power - 208V <30W
Economic - 208V < 250W
Standby - 0V until load connected...
I've played with it, not much use. Depending on item, they might not like the lower voltage. Some cf bulbs will not ignite with the lower voltage. The current draw on some things is not enough to allow the inverter to come out of standby. Some motor items might stall?
All modes will drain your batteries after a while (few days). I have the remote switches now which will allow you to put a switch on the dash or make it come on with the ignition. Best way.
When I'm back from sa I'll test and share them.
Sent from my GT-P7510 using Tapatalk
Rob
Well-Known Member
Crispin said:
I fully understand but this came straight from the manual and it clearly shows 240V neutral connected to the case:Justin_Elliott said:Yes - I meant don't connect the case to the 240v neutral
It just does not make any sense to me why they would suggest to connect the 240v neutral to the case then state to earth the case.
Rob
Well-Known Member
The above was taken from: http://images.mastervolt.nl/files/Manua ... 1000EN.pdf
Following those instructions and as the chassis and 12V negative are the same thing I have done the following:
I am beginning to think either I have misunderstood the manual or the manual is wrong
- Joined
- Feb 24, 2010
- Messages
- 6,131
- Country Flag
Guessing if the manual says so...
Wonder if there is anything between the negative terminal and the case. If you case is mounted to the chassis there would be a connection. Might it be bad?
I'll have a play as well as ask te guy I got them from what the installation would have been. They would have had to correct as it was a large company with 'elf and safety of the staff at steak.
Sent from my GT-P7510 using Tapatalk
Wonder if there is anything between the negative terminal and the case. If you case is mounted to the chassis there would be a connection. Might it be bad?
I'll have a play as well as ask te guy I got them from what the installation would have been. They would have had to correct as it was a large company with 'elf and safety of the staff at steak.
Sent from my GT-P7510 using Tapatalk
Don't like the adverts? Click here to remove them
- Joined
- Feb 24, 2010
- Messages
- 6,131
- Country Flag
So,
L -> N : 230V AC - as expected
N - > +12V : 115V AC - not expected
N - > negative : 115V AC - not expected
L - > +12V : 115V AC - not expected
L - > negative : 115V AC - not expected
I'm going to suggest that what is being see is half the sinewave (115X2=...) but putting it on the scope, it is a full sinewave so not sure.
No idea. I can't see it being a good thing in this type of installation (if the inverter case was not connected to the chassis I could understand it)
Rob, connect an inspection light between your Live and chassis. If all is well, the RCD will trip and everything is ok. Worst case, it will not and catch fire which means in a real situation, you would have been killed by the fault so in actual fact, you owe me
edit:
There is also nothing between the inverter chassis and the negative supply. They appear to be isolated. The blue line that you have could serve as a path if there is a fault on your negative wire.
If you negative lead comes loose and the inverter is connected to the chassis the path will now exist between chassis -> inverter -> your blue wire -> negative.
This [strike:2i5uu8sr]could[/strike:2i5uu8sr] would lead to a fire as it would not be strong enough.
L -> N : 230V AC - as expected
N - > +12V : 115V AC - not expected
N - > negative : 115V AC - not expected
L - > +12V : 115V AC - not expected
L - > negative : 115V AC - not expected
I'm going to suggest that what is being see is half the sinewave (115X2=...) but putting it on the scope, it is a full sinewave so not sure.
No idea. I can't see it being a good thing in this type of installation (if the inverter case was not connected to the chassis I could understand it)
Rob, connect an inspection light between your Live and chassis. If all is well, the RCD will trip and everything is ok. Worst case, it will not and catch fire which means in a real situation, you would have been killed by the fault so in actual fact, you owe me
edit:
There is also nothing between the inverter chassis and the negative supply. They appear to be isolated. The blue line that you have could serve as a path if there is a fault on your negative wire.
If you negative lead comes loose and the inverter is connected to the chassis the path will now exist between chassis -> inverter -> your blue wire -> negative.
This [strike:2i5uu8sr]could[/strike:2i5uu8sr] would lead to a fire as it would not be strong enough.
munster
Member
- Joined
- Aug 8, 2011
- Messages
- 128
The way the RCD operates is as follows
The phase and neutral cables from the supply to the load are passed through a magnetic ring called a toroid. On the toroid is wound a detector winding which is taken to a tripping mechanism. It is the make-up of this tripping mechanism which determines whether the RCD is electromechanical or electronic.
Whilst the current flowing down the phase conductor is balanced by that in the neutral the RCD takes no action but if part of the current flows down to earth through some metalwork or through a person's body an unbalance occurs between phase and neutral.
This causes a magnetic field in the toroid which is picked up by the detector winding, fed to the tripping mechanism and the RCD opens. It is this speed of opening, usually between 30 and 50 milliseconds, which gives the protection.
The operation of the electromechanical tripping mechanism. The mechanism consists of a permanent magnet which holds a tripping arm closed thus holding the RCD in the closed position.A spring attempts to pull the arm away from the magnet.
The Electrical Mechanical Device is called the RCCB, Residual Current Circuit Breaker.
A winding on the magnet is connected to the detector winding on the toroid and demagnetises the permanent magnet in the event of a signal on the detector winding due to a fault to earth.The arm is pulled away by the spring and the RCD trips.
In the case of the electronic RCD the signal from the toroid is fed into an electronic circuit which accepts the signal, amplifies it and instructs a relay to open the RCD.
In order to operate the electronic circuit a mains feed is required into the circuit to feed the amplifier etc and it is a requirement of the British Standard for electronic RCDs that if the supply to the electronic circuit fails and prevents its operation in the event of an earth fault the RCD must open. This is particularly important in the case of a loss of neutral which could cause the RCD not to work even though the phase supply is still connected to the load.
This problem does not arise in the case of the electromechanical RCCB in which the tripping is powered by the signal induced into the detector winding on the toroid.
A test circiut is connected from neutral to phase across the toroid and when the test button is pressed creates an unbalance of about 2.5 times the normal tripping current across the RCD which trips it. The use of the test button which should be operated at least quarterly verifies the operation of the RCD.
Additional Requirements for RCDs
Standard electromechanical RCCBs are designed to operate on normal supply waveforms and cannot be guaranteed to operate where none standard waveforms are generated by loads. The most common is the half wave rectified waveform sometimes called pulsating dc generated by speed control devices, semi conductors, computers and even dimmers.
The phase and neutral cables from the supply to the load are passed through a magnetic ring called a toroid. On the toroid is wound a detector winding which is taken to a tripping mechanism. It is the make-up of this tripping mechanism which determines whether the RCD is electromechanical or electronic.
Whilst the current flowing down the phase conductor is balanced by that in the neutral the RCD takes no action but if part of the current flows down to earth through some metalwork or through a person's body an unbalance occurs between phase and neutral.
This causes a magnetic field in the toroid which is picked up by the detector winding, fed to the tripping mechanism and the RCD opens. It is this speed of opening, usually between 30 and 50 milliseconds, which gives the protection.
The operation of the electromechanical tripping mechanism. The mechanism consists of a permanent magnet which holds a tripping arm closed thus holding the RCD in the closed position.A spring attempts to pull the arm away from the magnet.
The Electrical Mechanical Device is called the RCCB, Residual Current Circuit Breaker.
A winding on the magnet is connected to the detector winding on the toroid and demagnetises the permanent magnet in the event of a signal on the detector winding due to a fault to earth.The arm is pulled away by the spring and the RCD trips.
In the case of the electronic RCD the signal from the toroid is fed into an electronic circuit which accepts the signal, amplifies it and instructs a relay to open the RCD.
In order to operate the electronic circuit a mains feed is required into the circuit to feed the amplifier etc and it is a requirement of the British Standard for electronic RCDs that if the supply to the electronic circuit fails and prevents its operation in the event of an earth fault the RCD must open. This is particularly important in the case of a loss of neutral which could cause the RCD not to work even though the phase supply is still connected to the load.
This problem does not arise in the case of the electromechanical RCCB in which the tripping is powered by the signal induced into the detector winding on the toroid.
A test circiut is connected from neutral to phase across the toroid and when the test button is pressed creates an unbalance of about 2.5 times the normal tripping current across the RCD which trips it. The use of the test button which should be operated at least quarterly verifies the operation of the RCD.
Additional Requirements for RCDs
Standard electromechanical RCCBs are designed to operate on normal supply waveforms and cannot be guaranteed to operate where none standard waveforms are generated by loads. The most common is the half wave rectified waveform sometimes called pulsating dc generated by speed control devices, semi conductors, computers and even dimmers.
What voltage are you getting between the Earth pin on the inverter socket and the Live and the Neutral? When I served my time with ICI as a Tiffy all of the sockets in the research laboratories (old 5amp & 15amp round pin style) were fed using center tapped transformers so we fed 115v to each of the Live and the Neutral. This was for safety in the same way that we use 110v on construction sites in this country, if you put an electric meter between each of the Live and Neutral and earth on a site transformer you will get around 55v as these also are center tapped to earth. Maybe the Inverter is using the same principle hence your 115v readingCrispin said:So,
L -> N : 230V AC - as expected
N - > +12V : 115V AC - not expected
N - > negative : 115V AC - not expected
L - > +12V : 115V AC - not expected
L - > negative : 115V AC - not expected
I'm going to suggest that what is being see is half the sinewave (115X2=...) but putting it on the scope, it is a full sinewave so not sure.
No idea. I can't see it being a good thing in this type of installation (if the inverter case was not connected to the chassis I could understand it)
Rob, connect an inspection light between your Live and chassis. If all is well, the RCD will trip and everything is ok. Worst case, it will not and catch fire which means in a real situation, you would have been killed by the fault so in actual fact, you owe me
edit:
There is also nothing between the inverter chassis and the negative supply. They appear to be isolated. The blue line that you have could serve as a path if there is a fault on your negative wire.
If you negative lead comes loose and the inverter is connected to the chassis the path will now exist between chassis -> inverter -> your blue wire -> negative.
This [strike:ndbjbmeq]could[/strike:ndbjbmeq] would lead to a fire as it would not be strong enough.
- Joined
- Feb 24, 2010
- Messages
- 6,131
- Country Flag
So had a chat with the guy who I got them from.
Agrees that N->E is required as is a connection to real earth such as a spike in the soil (assuming you’re using the power outside of the truck). That gives a path back in the event of a fault and the RCD would trip. What he was unaware of is connecting the N to negative. Agreed that if you do, the connection should be at least as big as the negative feed.
Doing the first part and not the second will be fine if you’re outside but still leaves the truck chassis unprotected against earth faults.
TBH – I don’t know. Proceed with caution
Agrees that N->E is required as is a connection to real earth such as a spike in the soil (assuming you’re using the power outside of the truck). That gives a path back in the event of a fault and the RCD would trip. What he was unaware of is connecting the N to negative. Agreed that if you do, the connection should be at least as big as the negative feed.
Doing the first part and not the second will be fine if you’re outside but still leaves the truck chassis unprotected against earth faults.
TBH – I don’t know. Proceed with caution
Crispin said:Proceed with caution
Oh great, I'm full of confidence now...
So just to recap:
case to neutral = bad
case to negative = bad, unless cable is huge then maybe ok
case to 2ft ground spike dug in to surrounding soil = good
