(diy)Do I need a contactor?

[Christopher Parkinson]

Hi all, I'm building a small, home tanning bed. I finally have a staircase timer which works. It's rated at 16amps. I'm using 10 x 160watt lamps. There is an electronic ballast for each lamp. The ballasts are rated at 1 amp AC 230V output current. Do I need a contactor? The timer manufacturer sales guy says I need a contactor. Is that correct? It does not seem right to me. I'm only using 10 amps. Or am I missing something? If I need a contactor could someone give me a link to one on RS that I can use? It must be din rail type.

What should the breaker be rated at?

Supplementary question: I'm making a US version with 110v AC. There is a 110v version of the staircase timer. I forgot to ask what amperage it is. (I've just sent an email now). On the ballast for that one I've got: Max input current 0.60A @ 230v . (Not sure if the 230v is a mistake - it's a prototype so maybe is a mistake). Lamp Power . 1.96 - 160w. Lamp current 0.80 - 0.90A. What amperage breaker do I need? I think I need a contactor for this one. What amperage contactor do I need? Single pole or dual pole?

 

[davesparks]

You sure about PFC Dave? Thought it stood for Prospective Fault Current.
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PFC can be either prospe tove fault current or power factor question.
In this context Lucien mentioned a ballast having PFC built in, so logically must be describing power factor correction.

 

[Pete999]

PFC can be either prospe tove fault current or power factor question.
In this context Lucien mentioned a ballast having PFC built in, so logically must be describing power factor correction.

Maybe Lucien could offer a definitive answer, Lucien?
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PFC can be either prospe tove fault current or power factor question.
In this context Lucien mentioned a ballast having PFC built in, so logically must be describing power factor correction.

I guess this maybe one of the trades myriad of mistakes when using capitals as a description tests and descriptions

 

[davesparks]

Maybe Lucien could offer a definitive answer, Lucien?
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I guess this maybe one of the trades myriad of mistakes when using capitals as a description tests and descriptions

Well a ballast can't have a prospective fault current built in, that is a property of an electricity supply not a physical object you can build in to an item.
A ballast can however have power factor correction built in as this is done by adding components to the ballast.

 

[westward10]

In electrical engineering terms PFC primarily stands for Power Factor Correction. BS7671 does not use the acronym PFC nor is it listed under their abbreviations, prospective fault current is quoted in full and not by an abbreviation I suspect this is the reason why, as the acronym PFC is already utilised.

 

[Christopher Parkinson]

"I would be tempted to use someone with the necessary technical expertise to get this project up and running to be honest. Less risk than designing by web search, and you will end up with a good solution in less time."

>>I've tried 2 so called experts so far. The first one could not tell me why none of the 6 staircase timers I bought would work. It turns out that they needed a momentary push button timer to work. He also told me to use multi core wires on the basis that they were less likely to break. But as the electrician who I called out to get the timer working said: "You will have more chance of connecting things up right with single core. There are 11 connections for each lamp. You only need one bad connection for the lamp not to work"

I thought I had found someone else who was well qualified. (Electrical engineering degree). But he told me to buy a timer which was rated at 3,000 watts and that it would cope with powering the ballasts without having to use a contactor. But when I got the timer it says it's rated at 2,300 watt. Also, he gave me instructions for wiring it up which are not complete. (Where do the wires for the contactor switch go?). He also told me that I did not need a breaker because the fuse in the plug will suffice. But as far as I'm aware it's only UK plugs that have fuses. I intend to sell this thing worldwide.

So how do I find someone with the necessary expertise and how do I know they are a) competent and b) really want to help me. c) affordable

"...First off in the USA the voltage is 240/120,..."

Yes. I'd spotted that. The 240 is mainly for commercial though isn't it? A plug socket in a domestic setting will be 120v. Correct?

You do need to look closely at the load for the USA version, as it is nudging the 15A boundary. Is it intended to connect with a NEMA 5-15? If so, if the pf is good you're just in for running load with 5% below nominal as per NEC, (10 x 160 / 114 = 14A) but if the ballast will operate at say 100V it will go over the 15A. An MCB won't stop that happening and you would have to go up to a 5-20 which is less convenient for domestic users.
Source URL: (diy)Do I need a contactor? - https://www.electriciansforums.net/threads/diy-do-i-need-a-contactor.182902/

 

[davesparks]

I thought I had found someone else who was well qualified. (Electrical engineering degree). But he told me to buy a timer which was rated at 3,000 watts and that it would cope with powering the ballasts without having to use a contactor. But when I got the timer it says it's rated at 2,300 watt. Also, he gave me instructions for wiring it up which are not complete. (Where do the wires for the contactor switch go?). He also told me that I did not need a breaker because the fuse in the plug will suffice. But as far as I'm aware it's only UK plugs that have fuses. I intend to sell this thing worldwide.

So how do I find someone with the necessary expertise and how do I know they are a) competent and b) really want to help me. c) affordable

Yes. I'd spotted that. The 240 is mainly for commercial though isn't it? A plug socket in a domestic setting will be 120v. Correct?

Yes fused plugs are unusual in other countries (unless they use UK spec) but the plug fuse is only there to protect the flexible cable, it does not protect the appliance.

I doubt you'll find someone with the necessary expertise to design an appliance for numerous international markets and who understands the myriad regulations that go with it at an affordable price.

Are you aware of the requirements for CE marking and the low voltage directive to start with?

The USA uses 240/120 for domestic supplies, they have two phases with 240V between them and each at 120V to neutral. So their domestic circuits can be either 120V or 240V. They don't just have a single voltage and single type of socket outlet the way we do here.
Their commercial supplies can be other voltages too.

 

[Christopher Parkinson]

"....Are you aware of the requirements for CE marking and the low voltage directive to start with?..."

"...The new LVD does not require notified bodies to assess if products to be placed on the market comply with the applicable EU legislation. The manufacturer alone is responsible for determining this by carrying out conformity assessment procedures..."

How difficult can it be?

 

[DPG]

"....Are you aware of the requirements for CE marking and the low voltage directive to start with?..."

"...The new LVD does not require notified bodies to assess if products to be placed on the market comply with the applicable EU legislation. The manufacturer alone is responsible for determining this by carrying out conformity assessment procedures..."

How difficult can it be?

Have you read the requirements of the LVD in full?

 

[Christopher Parkinson]

Have you read the requirements of the LVD in full?

I tried to. It's mainly a load of guff from what I can see. Big corporations/banks pulling the strings to get us tied up in red tape so that you need huge amounts of capital to get anything off the ground.

(9)

The manufacturer, having detailed knowledge of the design and production process, is best placed to carry out the conformity assessment procedure. Conformity assessment should therefore remain solely the obligation of the manufacturer. There is no conformity assessment procedure in this Directive which requires the intervention of a notified body.

My assessment will be that it conforms.

 

[DPG]

I tried to. It's mainly a load of guff from what I can see. Big corporations/banks pulling the strings to get us tied up in red tape so that you need huge amounts of capital to get anything off the ground.

Not really. I'm thinking of the fault testing, safety of design, component approvals etc. It's not just a case of filling a form in and sticking a CE sticker on it.

 

[Christopher Parkinson]

The 240 is mainly for commercial though isn't it? A plug socket in a domestic setting will be 120v. Correct?

"..You do need to look closely at the load for the USA version, as it is nudging the 15A boundary. Is it intended to connect with a NEMA 5-15? If so, if the pf is good you're just in for running load with 5% below nominal as per NEC, (10 x 160 / 114 = 14A) but if the ballast will operate at say 100V it will go over the 15A. An MCB won't stop that happening and you would have to go up to a 5-20 which is less convenient for domestic users..."

OK. I understand most of that now I think. a 5-20 is more likely to be a cooker socket in the kitchen like our 32amp sockets, right? "...if the ballast will operate at say 100V.." Is this a scenario where the ballast is not operating like it should at 120 or is it a scenario where the voltage in the house is less than the nominal voltage? How likely do you think it will be for me to get away with it working with a NEMA 5-15? What do I have to measure and how do I measure to find out? If it doesn't they will have to run a cable from the kitchen right? (Not the end of the world but not a great selling point.) How would a Power Factor Corrector in the ballast work? Is it likely to already have one? What component or components make the PFC? Could one be added in line, externally?

 

[davesparks]

I tried to. It's mainly a load of guff from what I can see. Big corporations/banks pulling the strings to get us tied up in red tape so that you need huge amounts of capital to get anything off the ground.

(9)

The manufacturer, having detailed knowledge of the design and production process, is best placed to carry out the conformity assessment procedure. Conformity assessment should therefore remain solely the obligation of the manufacturer. There is no conformity assessment procedure in this Directive which requires the intervention of a notified body.

My assessment will be that it conforms.

But are you qualified to make the assessment or design the appliance?

It seems from this thread that you don't understand the basics of electrical science as taught in school science lessons, let alone the electrical safety of appliances.

You've mentioned many times that you will use a staircase timer to control the lamps, but what happens if the timer fails closed, what safety devices are you fitting to stop the lamps from being on too long and injuring the user?

 

[DPG]

Harsh words, but I've got to agree with Davesparks on this one. This needs the relevant experience and expertise, not a design-by-websearch approach.

 

[Megawatt]

"I would be tempted to use someone with the necessary technical expertise to get this project up and running to be honest. Less risk than designing by web search, and you will end up with a good solution in less time."











I thought I had found someone else who was well qualified. (Electrical engineering degree). But he told me to buy a timer which was rated at 3,000 watts and that it would cope with powering the ballasts without having to use a contactor. But when I got the timer it says it's rated at 2,300 watt. Also, he gave me instructions for wiring it up which are not complete. (Where do the wires for the contactor switch go?). He also told me that I did not need a breaker because the fuse in the plug will suffice. But as far as I'm aware it's only UK plugs that have fuses. I intend to sell this thing worldwide.

So how do I find someone with the necessary expertise and how do I know they are a) competent and b) really want to help me. c) affordable

"...First off in the USA the voltage is 240/120,..."

Yes. I'd spotted that. The 240 is mainly for commercial though isn't it? A plug socket in a domestic setting will be 120v. Correct?

You do need to look closely at the load for the USA version, as it is nudging the 15A boundary. Is it intended to connect with a NEMA 5-15? If so, if the pf is good you're just in for running load with 5% below nominal as per NEC, (10 x 160 / 114 = 14A) but if the ballast will operate at say 100V it will go over the 15A. An MCB won't stop that happening and you would have to go up to a 5-20 which is less convenient for domestic users.
Source URL: (diy)Do I need a contactor? - https://www.electriciansforums.net/threads/diy-do-i-need-a-contactor.182902/

Chris the voltage for homes is 240/120 the basic receptacles are 120vac. Commercial projects are usually 3 phase

 

[westward10]

From what I have gathered you have limited electrical knowledge but are intent on designing/manufacturing a tanning bed. I might understand your passion if you were showing the market a new concept but you are not, tanning beds have been about for decades and the market is saturated.