Electric Question

[Ohio-Ed]

ok, along the lines of an estop for my 50amp setup.. I'd need the switch and the contractor? For some reason, though I've read the thread already, my brain is not picking up on how it works.

To setup an e-stop like the on in the drawing that I posted here, you need a contactor (in your case rated for 50amps). You will also need a System Start button, and Emergency Stop button and a Relay (R1 in my drawing).

If you read the thread you'll see it took me a while to get my head around it also, but I promise you CodeRage did and excellent job working me through it. It is well worth it to understand how and why it works instead of someone just telling you what to buy and how to hook it up.

The kind of hard part to understand is that R1 latches the circuit... It kinda powers itself to hold the power on the contactor coil which makes the contactor close and provide power

 

[CodeRage]

Here is a 50 amp contactor at McMaster

This guy on e-bay has a whole lot. One of these would be great but he is selling them in lots of 3. Maybe send him an email
http://cgi.ebay.com/Square-D-8910DP...ultDomain_0?hash=item3ca9056c65#ht_2033wt_939

He might be able to hook you up if you tell him what you're looking for.

Contactors this large get kind of hard to define because they start to get measured in HP and that changes with the Line Voltage.

 

[Ohio-Ed]

Here is a 50 amp contactor at McMaster

This guy on e-bay has a whole lot. One of these would be great but he is selling them in lots of 3. Maybe send him an email
http://cgi.ebay.com/Square-D-8910DP...ultDomain_0?hash=item3ca9056c65#ht_2033wt_939

He might be able to hook you up if you tell him what you're looking for.

Contactors this large get kind of hard to define because they start to get measured in HP and that changes with the Line Voltage.

In looking for a contactor I noticed they are rated in Full Load and Resistive Load... Typically if you find a 50amp Full Load, it is rated at like 60 amp resistive load... Do we need to consider Full Load or is Resistive Load the number we are after ?

 

[CodeRage]

I would say Resistive load rating is okay to go by, considering only a small fraction of the load is inductive.

 

[Ohio-Ed]

I would say Resistive load rating is okay to go by, considering only a small fraction of the load is inductive.

I was afraid you'd say that... in that case, the one from Aubers should be good. It is rated at 50amp resistive. I probably got one much larger than needed.

 

[CodeRage]

I was afraid you'd say that... in that case, the one from Aubers should be good. It is rated at 50amp resistive. I probably got one much larger than needed.

Sorry bud, can't return it? What did you end up getting?

 

[Ohio-Ed]

Sorry bud, can't return it? What did you end up getting?

LOL... No problem. Well, I got a a 60amp, 3 pole.

Put then I paid a whopping 99 cents for it... plus $14 shipping. I found it on ebay with no bids.

If it is physically to big for my panel, I may just put it back up for sale.

But, as I'm thinking about it... how much current is required to hold the coil on one of these?

 

[whitescout]

I did a quick search, and it appears as though it has a 120 volt coil. No problems if the contactor is not too big to fit in your box. You can just use two of the three legs.

 

[CodeRage]

LOL... No problem. Well, I got a a 60amp, 3 pole.

Put then I paid a whopping 99 cents for it... plus $14 shipping. I found it on ebay with no bids.

If it is physically to big for my panel, I may just put it back up for sale.

But, as I'm thinking about it... how much current is required to hold the coil on one of these?

Does it have a VA rating on it?

 

[Ohio-Ed]

I don't have it yet and it was not listed on the auction.

 

[Baron ken]

I'm having a heck of a time finding a 30amp, 250volt fuse and holder(s) at a decent price. It looks like I can buy a double pole din mount breaker from AD for $18.75... Any reason why this wouldn't work for my 5500watt elements?

Here is the one I'm thinking of:
AD Breaker

Thanks,

Ed

Were you thinking of using this one breaker (2 pole) as F2 and F3 (also another for F4 and F5) from your diagram?

EDIT: how do you mount it in your enclosure?
EDIT2: would I need a 30A breaker/fuse for the element if I'm using a power cord with a built-in 30A GFCI breaker?

 

[Ohio-Ed]

Were you thinking of using this one breaker (2 pole) as F2 and F3 (also another for F4 and F5) from your diagram?

EDIT: how do you mount it in your enclosure?
EDIT2: would I need a 30A breaker/fuse for the element if I'm using a power cord with a built-in 30A GFCI breaker?

Yes I'm thinking of using the breaker in place of F2,F3 and F4,F5. If I use the breaker I linked, I would use a section of DIN Rail for mounting. The Relay Socket for R1 and the Heat Sinks for all the SSRs are DIN mountable, so I am thinking of using some DIN anyway.

You need a breaker/fuse to protect the wiring and devices in your panel. Any place you convert to a smaller gage wire or for any device you want to protect you need a fuse of the proper size.

I'm using a 50amp gfci breaker... a bunch of stuff in my panel could melt before the 50amp breaker ever trips.

Take a look at CodeRage's "Electrical Primer" thread.

Ed

 

[Baron ken]

Yes I'm thinking of using the breaker in place of F2,F3 and F4,F5. If I use the breaker I linked, I would use a section of DIN Rail for mounting. The Relay Socket for R1 and the Heat Sinks for all the SSRs are DIN mountable, so I am thinking of using some DIN anyway.

You need a breaker/fuse to protect the wiring and devices in your panel. Any place you convert to a smaller gage wire or for any device you want to protect you need a fuse of the proper size.

I'm using a 50amp gfci breaker... a bunch of stuff in my panel could melt before the 50amp breaker ever trips.

Take a look at CodeRage's "Electrical Primer" thread.

Ed

I've read that thread...good info.
I'm just trying to establish if a 30A breaker/fuse before the heater element would be of any additional benefit (for me) since I'm using a power cord with a 30A breaker built in. No sense to spend the money on the extra breaker if it's not needed.

And yes, I will put a fuse before my pump (your F7). 2A slow-blow?

 

[Ohio-Ed]

I've read that thread...good info.
I'm just trying to establish if a 30A breaker/fuse before the heater element would be of any additional benefit (for me) since I'm using a power cord with a 30A breaker built in. No sense to spend the money on the extra breaker if it's not needed.

And yes, I will put a fuse before my pump (your F7). 2A slow-blow?

If you are running 10 gage wire all the way to your element then you are probably OK. But I don't know what size element you have or what your wiring plan is. If you found a 2000 watt / 220 volt element and planned to run 14 gage wire to it then you need to have an additional fuse or breaker.
Make sense?

Ed

 

[MrShake]

30 amp fuse:
http://www.mcmaster.com/#71385k531/=5gi46v

Fuse Holder:
http://www.mcmaster.com/#7687k14/=5gi534

 

[Ohio-Ed]

30 amp fuse:
http://www.mcmaster.com/#71385k531/=5gi46v

Fuse Holder:
http://www.mcmaster.com/#7687k14/=5gi534

That would be perfect, Except... that is a time delay fuse.
I'm looking for a Fast Acting fuse.

I already have a fuse holder for 1/4" fuses but the FAST ACTING 30amp, 250volt fuse is elusive.

I'm thinking they have to be out there... I just can't find them??

Thanks,
Ed

 

[Baron ken]

If you are running 10 gage wire all the way to your element then you are probably OK. But I don't know what size element you have or what your wiring plan is. If you found a 2000 watt / 220 volt element and planned to run 14 gage wire to it then you need to have an additional fuse or breaker.
Make sense?

Ed

Makes sense, thanks.
My power cord w/ 30A breaker is 8 gauge. Heater element is 5500w. I plan to use 10 gauge wire from Contactor1 to the heater element (via an outlet and a 10 gauge dryer cord). However, I plan to use smaller gauge wire for the pump and other components, so I will definitely be using fuses for those.

 

[MrShake]

That would be perfect, Except... that is a time delay fuse.
I'm looking for a Fast Acting fuse.

I already have a fuse holder for 1/4" fuses but the FAST ACTING 30amp, 250volt fuse is elusive.

I'm thinking they have to be out there... I just can't find them??

Thanks,
Ed

http://www.mcmaster.com/#7059k463/=5gjk0k

 

[Ohio-Ed]

http://www.mcmaster.com/#7059k463/=5gjk0k

That is a Midget Fuse, not the 1/4" X 1.25" version. But that might be doable...
Those fuses are $2.96 each X2, + $8.66 for the Double Pole Holder = $14.58 VS $18.75 for the Double Pole Breaker from AD.

McMaster is usually pretty decent on shipping charges so that might not be bad. I found another site that had the Midget Fuses and Holders, total ended up over $42 (for both sets) with shipping vs ~$39 for the breakers from AD.

Thanks,
Ed

 

[Ohio-Ed]

OK, Here is the latest version of the drawing which includes LEDs for the 3-Position Selector switches. As drawn, the LEDs will light when power is applied to the Element or Pump regardless of weather in Hand or Auto mode.

I had to change some of the symbols to reduce the file size... the forum will only allow a 19.5kb PDF file! This is currently 19.3.

Let me know if you see anything of concern... I'm sourcing components now so there is still time to make design changes if needed.

Thanks
Ed

View attachment Visio-Panel v4.5.pdf

 

[CodeRage]

I'd build it!

 

[Ohio-Ed]

I'd build it!

That's the best stamp of approval I could hope for!

Thanks for ALL your help.

Ed

 

[Baron ken]

OK, Here is the latest version of the drawing which includes LEDs for the 3-Position Selector switches. As drawn, the LEDs will light when power is applied to the Element or Pump regardless of weather in Hand or Auto mode.

I had to change some of the symbols to reduce the file size... the forum will only allow a 19.5kb PDF file! This is currently 19.3.

Let me know if you see anything of concern... I'm sourcing components now so there is still time to make design changes if needed.

Thanks
Ed

I plan to use a 3-prong dryer cord for connecting to my heater element, using L1/L2 and ground to the BK. Where would that ground come into play in your schematic?

EDIT: I will have a 4-wire power cord (with 30A GFCI breaker) coming to my panel: L1/L2/N/GND, so I will have a GND bus, but I don't think that is the same as your GND bus connecting to the BCS (or is it?).

 

[Ohio-Ed]

I plan to use a 3-prong dryer cord for connecting to my heater element, using L1/L2 and ground to the BK. Where would that ground come into play in your schematic?

EDIT: I will have a 4-wire power cord (with 30A GFCI breaker) coming to my panel: L1/L2/N/GND, so I will have a GND bus, but I don't think that is the same as your GND bus connecting to the BCS (or is it?).

My drawing does not include the equipment ground. Your element ground should be tied to the ground from your GFCI, which should also be bonded to the chassis of your panel.

There "should" be no problem sharing the equipment ground and the BCS ground but they don't have to be connected. It "could" increase the chance of noise in the BCS DC circuits by tying the grounds together.

I will probably keep them separate.

Ed

 

[CodeRage]

My drawing does not include the equipment ground. Your element ground should be tied to the ground from your GFCI, which should also be bonded to the chassis of your panel.

There "should" be no problem sharing the equipment ground and the BCS ground but they don't have to be connected. It "could" increase the chance of noise in the BCS DC circuits by tying the grounds together.

I will probably keep them separate.

Ed

Yeah, the power supply you use for the BCS may not bond the DC 0V bias to ground, so there is no guarantee that earth ground and DC ground are actually bonded. Doing this could cause nuisance gfci trips as well.

 

[Baron ken]

... I'm sourcing components now so there is still time to make design changes if needed.

What will you be using for your buses (distribution blocks/terminal barrier strips etc.)?

 

[Baron ken]

Since relay1 is rated at 5A, will a fuse be needed along that path, e.g. before the e-stop?
If so, what about the path that connects L2 to the other set of the relay1 contacts as well?
And if that one requires a fuse too, could you connect both sets of relay1 contacts to the same incoming L2 (i.e. the path after the e-stop) and then only 1 fuse would be needed?

 

[CodeRage]

Since relay1 is rated at 5A, will a fuse be needed along that path, e.g. before the e-stop?
If so, what about the path that connects L2 to the other set of the relay1 contacts as well?
And if that one requires a fuse too, could you connect both sets of relay1 contacts to the same incoming L2 (i.e. the path after the e-stop) and then only 1 fuse would be needed?

I think you're confused.

R1 never touches L2. the coil goes between L1 and Neutral.

Here is how the circuit works.

The e-stop is normally closed, so it is passing current to the start button and R1 contant.
The run button is momentary, so after you lift your finger the circuit opens again.
When you press the run button it completes the circuit to the coil of R1

R1 closes it's contacts, one of which energizes C1 allowing current to pass down L1 and L2 to the rest of the devices.
The second contact of R1 closes bypassing the momentary start button. So when you left your finger and the contacts open R1 will keep it self energized.

When you press the E-Stop it break the circuit going to R1's coil, in turn breaking C1's coil, which ultimately disconnects power from the rest of the brewery.

To start the system again the E-stop needs to be reset and the start button pressed again.

As far as fusing goes, The wire going to the coil needs to be protected from running an over current.

When you get to devices like relays, you don't have to use a fuse for each individual one, you can fuse a terminal bus to the rating of the wire used for the relays. So if it is 14Awg, you would put a 15 amp fuse on it. After that fuse you can use 14Awg wire to control up to as many relays 15amps will support. Say the coil draws .1 Amps to energize, you could use that 15 Amp bus to power 15A/.1A*.50 Relays (that would be 150 relays derated by 50% to avoid nuisance pops, 75 relays)

Same goes for the contactors.

Does this help or have I muddied the waters?

 

[Baron ken]

I think you're confused.

R1 never touches L2. the coil goes between L1 and Neutral.

I was referring to Visio-Panel v4.5.pdf and it does look like L2 connects to R1. The coil is connected thru the e-stop and the momentary PB and also one of the contacts is connected directly to L2. Help me out here if I'm reading it wrong.

Here is how the circuit works.

The e-stop is normally closed, so it is passing current to the start button and R1 contant.
The run button is momentary, so after you lift your finger the circuit opens again.
When you press the run button it completes the circuit to the coil of R1

R1 closes it's contacts, one of which energizes C1 allowing current to pass down L1 and L2 to the rest of the devices.
The second contact of R1 closes bypassing the momentary start button. So when you left your finger and the contacts open R1 will keep it self energized.

When you press the E-Stop it break the circuit going to R1's coil, in turn breaking C1's coil, which ultimately disconnects power from the rest of the brewery.

To start the system again the E-stop needs to be reset and the start button pressed again.

I understood all of that. Your primer and this thread have made it nice and clear how the e-stop/momentary/relay/contactor work. Thanks.

As far as fusing goes, The wire going to the coil needs to be protected from running an over current.

When you get to devices like relays, you don't have to use a fuse for each individual one, you can fuse a terminal bus to the rating of the wire used for the relays. So if it is 14Awg, you would put a 15 amp fuse on it. After that fuse you can use 14Awg wire to control up to as many relays 15amps will support. Say the coil draws .1 Amps to energize, you could use that 15 Amp bus to power 15A/.1A*.50 Relays (that would be 150 relays derated by 50% to avoid nuisance pops, 75 relays)

Same goes for the contactors.

Does this help or have I muddied the waters?

Ok, so I'm thinking I can put a fuse (rating to be determined once I source the relay and contactor) between L2 (depending on how you answered the first part above) and the e-stop and then split the path after the e-stop going to both of the R1 contacts and the momentary PB. Pressing the e-stop in this case would cut power to both contacts of R1 (and subsequently C1) and also cut power to R1's coil which would de-energize the contacts and keep C1 off.
Now, have I muddied the waters as well?

 

[CodeRage]

Ok, so I'm thinking I can put a fuse (rating to be determined once I source the relay and contactor) between L2 (depending on how you answered the first part above) and the e-stop and then split the path after the e-stop going to both of the R1 contacts and the momentary PB. Pressing the e-stop in this case would cut power to both contacts of R1 (and subsequently C1) and also cut power to R1's coil which would de-energize the contacts and keep C1 off.
Now, have I muddied the waters as well?

I was going from memory and thought it was on L1 and when I saw L2 I thought you were talking as if it was driven between L1 and L2. My mistake.

So I think your question is what kind of fuse protection is needed for that circuit?

Now that you brought it up.
Well, if the relay contact is only 5 amps then I would tap off of L2, through a 2 amp fuse (slow blow) and into a control power distribution block. Then use the control power distribution block to power the E-stop circuit and the Coil circuit for C1.

Sorry Ed, you may want to consider this too. With the parts you have you could replace F1 with a 1.5 or 2A SB and tap off of there instead of L2.