New RCD Unit
- Thread starter garash
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A consumer unit costs between £30 and £300 to buy and with cost between £30 and £300 to fit, and to swap a MCB for a RCBO could cost as little as £10 for the unit and £10 to fit, a plug in RCD can cost £8, so your question is far too open to really be answered. What do you want?
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My son fitted mine, I don't have the dexterity to work in the confined space between ceiling and roof required to extend all the cables, so no labour charge, and the enclosure with 16 RCBO's an isolator and a surge protection unit cost around £250, because the consumer unit is in the flat under the house, did not want to be forced to go outside in middle of night to reset a RCD, plus large house and two RCD's would not be enough.
However my first house had just 4 fuses, so the most direct replacement would be this one from Screwfix at £59.90 plus fitting likely ½ a day to fit it. Personally I would not want to fit it, a Part populated CU costs from Screwfix £26.49 and a RCBO costs £23.99 so 4 RCBO plus box = £122.45 I know I paid £10 each for the RCBO's I used so clearly you can get it for less than that, but wanted to compare basic to good quality so wanted to price from same supplier, so extra £62.55 for a quality job, since likely paying £120 labour for even simplest install it seems false economy to do it on the cheap.
So what you really need is a comparison all RCBO to two RCD, you can get what is called a high integrity board which mixes the two, but keeping it simple, I will try to explain.
So the RCBO is a RCD and MCB combined, the problem is with three devices in one, you don't know if tripped on magnetic overload, thermal overload, or imbalance, however imbalance is most likely, so the problem in real terms is very small. And it means when it trips you only loose that circuit, all others carry on working, so no problem with a faulty iron causing the lights to fail.
The other thing is all cables with AC current have some capacitance and inductive coupling so there is always some leakage current, a 30 mA RCD will trip between 15 and 30 mA, and it is recommended no more than 9 mA leakage per RCD so with say 4 MCB's you can have 2 mA each and be within the limits, however with 4 RCBO's you can have 9 mA each, so the chances of them tripping to start with is much reduced. Not counting faults, as where there is a fault it is just doing its job, I have never had a RCBO trip, but over 30 years of having RCD's in last house I would say average trip once every 6 months. Not really that bad as most of the time there when tripped, but over that 30 years lost two freezer full of food, which cost us around £400 to replace the food, plus in early years the freezer did not record the highest temperature like they do today, so we may have eaten food which had part de-frosted.
As to the number of times I have had to get up in middle of night and get dressed to go out to garage to reset the RCD I have lost count, with a RCBO if not lights or freezer it can wait until morning, with RCD it will always affect one so you have to reset.
The problem is until you have a RCD fitted you have no idea how often it will trip, mothers house was mixture RCD and RCBO and the RCBO's never tripped, and the RCD tripped once in 3 years, so was not really an issue. Before the rewire they had a RCD on just the wet room and shower, I know my dad cursed at having to come down stairs and reset it, after he died we found a leak in roof with was likely cause of tripping, but still he did not know that.
The intermittent fault is harder to find the more is on each RCD, my daughter had a trip and in the end the fault did not clear, it was found there was a nick on the neutral wire on one socket which was touching the fixing screw which was earthed, with test equipment it took me 4 hours to find, yes the RCD makes the house safer, but they can also be a pain when you can't find out why they have tripped.
My house seemed to go in batches, as said fitted for 30 years, would go three years without tripping, then trip once a week for a month, then another two years before next trip, and no fault found. There is some luck, and size of house matters, but you need to consider RCD or RCBO route as it is expensive to change latter.
However my first house had just 4 fuses, so the most direct replacement would be this one from Screwfix at £59.90 plus fitting likely ½ a day to fit it. Personally I would not want to fit it, a Part populated CU costs from Screwfix £26.49 and a RCBO costs £23.99 so 4 RCBO plus box = £122.45 I know I paid £10 each for the RCBO's I used so clearly you can get it for less than that, but wanted to compare basic to good quality so wanted to price from same supplier, so extra £62.55 for a quality job, since likely paying £120 labour for even simplest install it seems false economy to do it on the cheap.
So what you really need is a comparison all RCBO to two RCD, you can get what is called a high integrity board which mixes the two, but keeping it simple, I will try to explain.
So the RCBO is a RCD and MCB combined, the problem is with three devices in one, you don't know if tripped on magnetic overload, thermal overload, or imbalance, however imbalance is most likely, so the problem in real terms is very small. And it means when it trips you only loose that circuit, all others carry on working, so no problem with a faulty iron causing the lights to fail.
The other thing is all cables with AC current have some capacitance and inductive coupling so there is always some leakage current, a 30 mA RCD will trip between 15 and 30 mA, and it is recommended no more than 9 mA leakage per RCD so with say 4 MCB's you can have 2 mA each and be within the limits, however with 4 RCBO's you can have 9 mA each, so the chances of them tripping to start with is much reduced. Not counting faults, as where there is a fault it is just doing its job, I have never had a RCBO trip, but over 30 years of having RCD's in last house I would say average trip once every 6 months. Not really that bad as most of the time there when tripped, but over that 30 years lost two freezer full of food, which cost us around £400 to replace the food, plus in early years the freezer did not record the highest temperature like they do today, so we may have eaten food which had part de-frosted.
As to the number of times I have had to get up in middle of night and get dressed to go out to garage to reset the RCD I have lost count, with a RCBO if not lights or freezer it can wait until morning, with RCD it will always affect one so you have to reset.
The problem is until you have a RCD fitted you have no idea how often it will trip, mothers house was mixture RCD and RCBO and the RCBO's never tripped, and the RCD tripped once in 3 years, so was not really an issue. Before the rewire they had a RCD on just the wet room and shower, I know my dad cursed at having to come down stairs and reset it, after he died we found a leak in roof with was likely cause of tripping, but still he did not know that.
The intermittent fault is harder to find the more is on each RCD, my daughter had a trip and in the end the fault did not clear, it was found there was a nick on the neutral wire on one socket which was touching the fixing screw which was earthed, with test equipment it took me 4 hours to find, yes the RCD makes the house safer, but they can also be a pain when you can't find out why they have tripped.
My house seemed to go in batches, as said fitted for 30 years, would go three years without tripping, then trip once a week for a month, then another two years before next trip, and no fault found. There is some luck, and size of house matters, but you need to consider RCD or RCBO route as it is expensive to change latter.
WonderWeb cannot live without it.,
https://www.instructables.com/id/How-to-Use-Hemming-Tape-Wonderweb-on-Trousers/
Upwards of £700
At a complete guess
If you mean a new fuse box consumer unit
At a complete guess
If you mean a new fuse box consumer unit
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