Not enough power from standard wall outlet - Page 1
Forum section: electronics / general

author: beeboopbeep
author_rank: Contributor
timestamp: August 15, 2018, 04:37:04 am
content: Hi everyone,I'm trying to power a reflow oven but am running into power issues with the standard Canadian wall outlet. I didn't realize this but the limit for the wall outlet is usually less than 15 A at 120 V AC (the oven requires approximately 2400 W and is configured for 110 V AC input). So, my next go to solution was thinking of connecting the reflow oven to the NEMA 14-30 wall outlet used for the dryer (I'm still reading up on how the NEMA 14-30 is wired and if other possible solutions exist using regular wall outlets). I was also wondering if there is a device that will connect multiple wall outlets with different phases/fused networks and can provide one single 110 V AC with boosted power.Has anyone ran into a similar issues and if so, how were you able to solve it? Any advice would be greatly appreciated!

author: TheSteve
author_rank: Unknown
timestamp: August 15, 2018, 04:42:16 am
content: Modern houses should have 20 amp service to the kitchen outlets. Not sure about businesses, if they do have 20 amp service the outlet should look like the picture attached.

author: DerekG
author_rank: Frequent Contributor
timestamp: August 15, 2018, 04:44:40 am
content: Quote from: beeboopbeep on August 15, 2018, 04:37:04 amCheck the fixed cable suppling your power point. It will likely have some Standards markings on it (unless it is quite old). Look-up the Standard & you will see what it is rated at.In Australia, the cable would likely be rated at 40A, even though the power point socket is only rated at 10A or 15A.If the cable can take a higher rating, install a higher capacity power point, or hard wire your oven. Make sure you don't overload the rating of the cable by turning on too many other appliances at the same time. The cable should contain a fuse or circuit breaker at the power box of course

author: Bratster
author_rank: Frequent Contributor
timestamp: August 15, 2018, 04:53:48 am
content: Your best bet is wiring a plug on to it for that 14-30 outlet.Using one of the lines, the neutral, and the ground.Edit: double check and be sure you know what you are doing if you are going to go this route and wiring it up. That 14-30 outlet has 240 volts on it as well as 120 depending on how you wire it.there's no way to combine power from multiple outlets in any remotely safe fashion.the wiring in your walls feeding the outlets is either going to be 14 gauge which can do 15 amps or 12 gauge which could do 20 amps.And trying to draw a full 20 amps on a regular household 20 amp circuit is not recommended.Sent from my Fi Moto x4 using Tapatalk

author: TERRA Operative
author_rank: Super Contributor
timestamp: August 15, 2018, 05:12:21 am
content: Quote from: DerekG on August 15, 2018, 04:44:40 amNormal outlets are rated to 10A, and as a rule of thumb, 2.5mm^2 CCA in-wall power cable is rated to 20A after usual deratings are applied.Thicker cable as used for ovens (6mm^2 CCA etc) is rated to around 40A or so.

author: Brumby
author_rank: Unknown
timestamp: August 15, 2018, 05:19:17 am
content: This:Quote from: Bratster on August 15, 2018, 04:53:48 amAlso - do NOT contemplate anything with "other phases" as this will take you into territory where the voltages will be anythingBUT120V. Even the so-called "split phase" seen a lot around the USA (is Canada the same?) provides 240V in addition to the standard 120V.

author: Bratster
author_rank: Frequent Contributor
timestamp: August 15, 2018, 05:36:44 am
content: Quote from: Brumby on August 15, 2018, 05:19:17 amThat too^I'm pretty sure Canada is almost identical to the US for most of the AC power related things. They obviously have different codes but I'm pretty sure the underlying system is the same.Sent from my Fi Moto x4 using Tapatalk

author: Ian.M
author_rank: Super Contributor
timestamp: August 15, 2018, 05:57:03 am
content: Quote from: beeboopbeep on August 15, 2018, 04:37:04 amCan the oven be reconfigured for 220V AC input? If so, it can be run phase to phase on the NEMA 14-30 outlet, at half the current for the same power.Alternatively, if the control circuit is optoisolated from the heating elements (e.g. by SSRs) it may be possible to split the heating elements into two groups to run at 110V and fit another mains lead to power half of the heating elements from a second ordinary NEMA 5-15R wall socket.However you need to be 100% certain that the two groups of elements are totally isolated from each other and can pass a HiPot insulation test to ground, as otherwise it would effectively be a 'suicide cord' with a lump in the middle!

author: gnif
author_rank: Unknown
timestamp: August 15, 2018, 06:01:59 am
content: Also don't forget that if what you're doing causes a fire, it will very likely void any insurance you have.

author: Red Squirrel
author_rank: Super Contributor
timestamp: August 15, 2018, 06:37:14 am
content: I would run a dedicated 20 amp outlet. A 20 amp outlet will provide 2400w. Though that is kinda cutting it close. Another option might be a 30 amp twistlock which will provide 3600w so more breathing room. I personally would not do a dryer outlet as those are split phase, so using one for a 120v only item seems dirty to me. I mean, it would work, you just use one of the "phases" but I don't like the idea myself. Run a proper 120v only circuit, unless the oven can be configured for 240v. Then a 240v 15 amp circuit would do the trick.Though question is, does the oven actually DRAW 2400w or is it just rated for that? If it's just rated for that, then the 20a 120v outlet would be your simplest bet. Since it's cutting it so close I would use 10 gauge wire, that way if you do end up needing to bump it up to a 30 amp, you can.

author: beeboopbeep
author_rank: Contributor
timestamp: August 15, 2018, 01:58:33 pm
content: Quote from: TheSteve on August 15, 2018, 04:42:16 amI see that the fuses for connecting to the kitchen is double the current of regular fuses (e.g., to living room) but the wall outlets are not that type of outlets in the picture.Quote from: Bratster on August 15, 2018, 04:53:48 amThe three wires provided on the reflow oven are for hot, neutral, and ground. Looking from the NEMA 14-30 outlet labels (as shown here:http://www.generatorsforhomeuse.us/wp-content/uploads/nema14-30r.jpg), it looks like I can get away with wiring the reflow oven to the three plugs (i.e., hot to 'Line 1', netural to 'Neutral', and ground to 'Ground'), excluding the 'Line 2'. I'll be measuring the voltage with my multimeter between 'Neutral' and 'Line 1' to ensure I'm getting approximately 120 V rms.Quote from: Ian.M on August 15, 2018, 05:57:03 amAs noted above, I was thinking of wiring it so that I can get 120 V rms from the NEMA 14-30 for the oven.Quote from: Red Squirrel on August 15, 2018, 06:37:14 amIt's actually rated for 2900 W but it states it can use up to 2400 W (confusing... I know..). For safety reasons, I'm going to assume it can consume up to 2900 W.

author: NiHaoMike
author_rank: Super Contributor
timestamp: August 15, 2018, 02:30:56 pm
content: I find it strange that something that uses more than 1800W or so would even have the option of running from 120V.

author: Brumby
author_rank: Unknown
timestamp: August 15, 2018, 03:17:01 pm
content: Quote from: NiHaoMike on August 15, 2018, 02:30:56 pmThere was something at the back of my mind that I couldn't quite put my finger on. That was it.

author: Bratster
author_rank: Frequent Contributor
timestamp: August 15, 2018, 03:36:47 pm
content: That is slightly odd. However 120 volt 30 amp circuits are not uncommon in More commercial type scenarios.Sent from my Fi Moto x4 using Tapatalk

author: beeboopbeep
author_rank: Contributor
timestamp: August 15, 2018, 04:30:32 pm
content: Thanks everyone for your help!I'll be buying one of thesehttps://www.amazon.ca/gp/product/B00MHOFTLM/ref=ox_sc_act_title_1?smid=A3DWYIK6Y9EEQB&psc=1and connecting the Line 1, neutral and ground (as first suggested by Braster) to the reflow oven and it looks like everything should work without issues.EDIT: does anyone know by any chance what bolt and nut size the ring terminals is designed for?

author: james_s
author_rank: Super Contributor
timestamp: August 15, 2018, 04:44:11 pm
content: Canada and USA are nearly identical as far as domestic electrical wiring goes. I don't know anything about the Canadian codes but all the hardware looks the same.Generally you find either 15 or 20A circuits feeding 120V receptacles, and you can have 15A receptacles on a 20A circuit. The only real difference is that 20A receptacles will allow a 20A plug to be inserted although I've never actually seen a 20A 120V plug on any consumer device.The dryer cord should work fine, as I recall the terminal bolts are typically 1/4-20 size but you could also snip off the terminals and install something else.I will echo the other post that it's unusual to see anything 120V that draws that much power, normally a given appliance will not draw more than 15A, unless it's something that comes with a 20A plug. 30A 120V plugs are commonly used for shore power connection on boats and RVs but in houses anything above 20A is usually 240V. If it has a neutral though you can do what you're doing and get 120V 30A out of it ignoring one of the hot wires. In older houses it's common for the dryer socket to have only the two hots and ground with no separate neutral but I think NEC requires the neutral now.

author: Cubdriver
author_rank: Unknown
timestamp: August 15, 2018, 08:17:23 pm
content: If I were in your shoes, I'd run a dedicated 30A, 120V circuit to a NEMA 5-30 receptacle, rather then trying to Mickey-mouse things with a dryer or range cord.-Pat

author: james_s
author_rank: Super Contributor
timestamp: August 15, 2018, 09:03:51 pm
content: In an ideal world sure, but running a dedicated circuit is hardly practical in a lot of cases. Nothing wrong with using a properly made adapter to plug into a dryer socket. This isn't rocket science.

author: tpowell1830
author_rank: Frequent Contributor
timestamp: August 16, 2018, 02:44:22 am
content: Quote from: beeboopbeep on August 15, 2018, 04:37:04 amAlthough your original idea should work with the 30 amp outlet, you could be violating electrical codes in your area by doing this. You need to view this special circuit from end to end. Start with a 30 amp breaker, the wiring should be rated at 30 amps as well (10 AWG). The next step is calculating voltage drop under load based on the length of the wiring run.Secondarily, in your case, the power cord to the device needs to be rated for at least 20 amps, so the power cord wire gage needs to be at least 12 AWG. The power plug on the device needs to be rated at minimum 20 amps as well.This leads me to ask the obvious question: Is the device rated for 120/240 volts depending on heating element wiring configuration? I would definitely check this out. If the electronics control is 120 VAC then a 240 VAC circuit is simply 2 - 120 VAC circuits (at 180° phase difference). This is not a problem if part of your device is depending on a 120 VAC input (i.e. a 120 VAC hot and a neutral) because the NEMA 14-30 is a 4 wire receptacle. Even if the device can be driven with 240 VAC, which would then only be a 10 amp draw, according to code, your receptacle circuit will still need to meet the 30 amp requirement which means 10 AWG wire. This is for safety in case someone plugs a 30 amp device into this receptacle.Many devices with multiple elements can be rewired in either a series or parallel configuration to meet voltage/current requirements. It is simply a matter of moving jumpers to reconfigure the element input voltage. For example, a device with 2 elements in parallel that produces 2400W at 120 VAC can be reconfigured to produce 2400W at 240 VAC by rewiring the elements into series.Hope this helps...

author: james_s
author_rank: Super Contributor
timestamp: August 16, 2018, 03:09:39 am
content: Electrical codes shouldn't be an issue with something that plugs into a socket, as far as I know code only dictates the built in part of the installation. That's not to say that one should throw caution to the wind but I wouldn't worry about code in this case. Fuse the appliance appropriately to protect the cord on it.

author: stj
author_rank: Super Contributor
timestamp: August 16, 2018, 01:05:11 pm
content: you should be using IEC309 connectors for that power.the NEMA junk is just rubbish.only takes a min to fit too

author: beeboopbeep
author_rank: Contributor
timestamp: August 16, 2018, 02:50:49 pm
content: I just wanted to provide a quick update! The reflow oven works! I've attached a pic of the final result on a spare board with 4 components if anyone is interested.Quote from: tpowell1830 on August 16, 2018, 02:44:22 amQuote from: james_s on August 16, 2018, 03:09:39 amThank you both for the info. I'll ask a lab manager I know from my university since he knows the building code very well. I wouldn't want any issues with insurance and such if the machine for some reason caused a fire. Also, it has a fuse for 32 A and it's marked 'CE' but I don't know how much I trust that certification (I'm guessing it's either 'self' certified or the China's 'knockoff' certification).

author: In Vacuo Veritas
author_rank: Frequent Contributor
timestamp: August 16, 2018, 03:06:24 pm
content: Looks terrible. More work needed.

author: beeboopbeep
author_rank: Contributor
timestamp: August 16, 2018, 03:11:40 pm
content: Quote from: In Vacuo Veritas on August 16, 2018, 03:06:24 pmAny tips? Also, I didn't have a stencil so I was trying to spread the solder paste with a toothpick which I guess made it look worse than it already was..

author: In Vacuo Veritas
author_rank: Frequent Contributor
timestamp: August 16, 2018, 03:18:58 pm
content: Quote from: beeboopbeep on August 16, 2018, 03:11:40 pmThat explains it... Once you dial it in and use the correct stencil it should look much better.

author: james_s
author_rank: Super Contributor
timestamp: August 16, 2018, 04:47:35 pm
content: Quote from: stj on August 16, 2018, 01:05:11 pmThose are indeed nice, but not widely available in North America. The NEMA stuff can be purchased in any hardware store and it does work even though I agree it is inferior.

author: stj
author_rank: Super Contributor
timestamp: August 16, 2018, 05:09:05 pm
content: they arent too hard to find, although u.s. distributors will rob you.you can order from european or chinese suppliers for very low costs.a 32A plug is only about €5 for i.p.44 and maybe double for i.p.67 for example.i like PCE brand myself - they are budget end but good build quality.btw, if you can get into a closed-down mcdonalds then you can salvage loads of them!! all mcdonalds worldwide afaik like to use them.

author: basinstreetdesign
author_rank: Frequent Contributor
timestamp: August 16, 2018, 08:15:42 pm
content: Quote from: NiHaoMike on August 15, 2018, 02:30:56 pmI agree.The first thing I would do is to investigate if your oven can be configured for 240 V operation. If it can, do that.Running it on 120 through a 35 A fuse will seriously unbalance your houses electrical system. All electricians recognize that the electrical system of a house is connected to the 240V center-tapped secondary of a pole transformer. All of the 120 V loads are put in each side of the center-tap in an effort to keep the secondary load balanced. 240V loads are connected across the full winding, that is, the two "hots". So some 120V wall outlets are on each side. That is why some people have measured 240 between neighbouring wall outlets in a kitchen, for instance. Putting a heavy load on only one side will seriously unbalance the pole transformer secondary and put a lot of current through the nuetral. This will get electricians mad at you and put your insurance at risk. (And seeing how insurance companies will take any excuse to deny payout, that could turn into a nasty court case that could drag forever and then you would eventually lose.)

author: james_s
author_rank: Super Contributor
timestamp: August 16, 2018, 09:08:08 pm
content: The balance won't really matter in most cases. While there is some attempt made to balance the loads in the panel, there is nothing stopping a person from running a bunch of heavy loads on circuits that all happen to be on one side of the panel. Certainly a 30A imbalance is not going to be an issue with most houses that have the standard 200A panel and if it does become a problem it's easy to move one or more of the 120V circuits to the other bus in the panel.

author: metrologist
author_rank: Super Contributor
timestamp: August 17, 2018, 12:08:06 am
content: Quote from: james_s on August 15, 2018, 04:44:11 pmYou might see the high current plug on a microwave. That is one of two outlets in my house that take that plug. The other is by the back garage door. I'm disappointed because I just got a 10 outlet power strip and it has one blade rotated, so I can't really use it...

author: james_s
author_rank: Super Contributor
timestamp: August 17, 2018, 12:41:06 am
content: Well if the circuit is 20A there's nothing wrong with installing a 20A receptacle to make use of your power strip.

author: Red Squirrel
author_rank: Super Contributor
timestamp: August 18, 2018, 01:07:56 am
content: Quote from: james_s on August 15, 2018, 09:03:51 pmHave to run a dedicated circuit either way though, since it needs 10 gauge wiring.

author: Cyberdragon
author_rank: Super Contributor
timestamp: August 18, 2018, 03:23:43 am
content: Quote from: beeboopbeep on August 16, 2018, 03:11:40 pmThere's also some oddly misshapen traces near the left. Etching issues or is that the solder mask?

author: james_s
author_rank: Super Contributor
timestamp: August 18, 2018, 03:34:22 am
content: Quote from: Red Squirrel on August 18, 2018, 01:07:56 amHe has a dryer circuit, that's already wired with the appropriate wiring. There's no need to run a dedicated circuit, a suitable circuit is already present.

author: Red Squirrel
author_rank: Super Contributor
timestamp: August 18, 2018, 03:47:39 am
content: Quote from: james_s on August 18, 2018, 03:34:22 amThat sounds like a pain having to unplug dryer and drag the oven down to laundry room each time though. But I guess whatever works.

author: james_s
author_rank: Super Contributor
timestamp: August 18, 2018, 05:02:57 am
content: Well I unplug my dryer to plug in my welder, it's not a big deal for something that isn't used all the time and it's a whole lot less of a pain than running a new circuit which in my place would require opening up several walls, no idea about his place.

author: Vtile
author_rank: Super Contributor
timestamp: August 18, 2018, 11:13:00 am
content: It is interesting to follow these N.A electrical problems.

author: Bratster
author_rank: Frequent Contributor
timestamp: August 18, 2018, 05:06:50 pm
content: for all we know he may be using a gas dryer which is more common where I am, (gas is cheaper than electricity hear), even though most houses are wired for electric dryers as well.All depends on where you live, I know more east coast of the US gas is not nearly as prevalent so electric is more popular.And it may be in the garage and not a laundry room. which would be a good spot to set up a Reflow oven anyway.That's how my house is, dryer Outlet in the garage but a gas dryer. so i wired up a heavy duty 10/4 extension cord to plug in there and that goes over to my work bench for running any high power 120 volts or 240 volt devices.Which at the moment is just my welder.Sent from my Fi Moto x4 using Tapatalk

author: stj
author_rank: Super Contributor
timestamp: August 18, 2018, 05:16:17 pm
content: instead of unplugging, why not fit a second outlet bellow or beside the existing one?current etc. wont be an issue if you dont use both devices at the same time.

author: james_s
author_rank: Super Contributor
timestamp: August 18, 2018, 05:40:08 pm
content: Well in his original post he said he bought a dryer cord to make an adapter, which strongly implies that he does in fact have an electric dryer with an existing circuit, otherwise it would not make any sense to take such an approach.Installing a second socket is certainly a workable solution. I don't know offhand if code allows that but it shouldn't be a safety issue if done properly. In my case anyway I only weld something at home once in a blue moon so it's not a big deal. Unplugging the dryer is the easy part, I spend most of the time looking for my gloves, cleaning the dust and spiders out of my mask and remembering how to set up the machine for what I want to do.

author: Bratster
author_rank: Frequent Contributor
timestamp: August 18, 2018, 06:04:46 pm
content: Quote from: james_s on August 18, 2018, 05:40:08 pmIt doesn't necessarily imply that he has an electric dryer. Again it depends on where you live.Out my way houses routinely come with both Gas and Electric hookups for the dryer.Sent from my Fi Moto x4 using Tapatalk

author: james_s
author_rank: Super Contributor
timestamp: August 18, 2018, 06:11:05 pm
content: Well the important part is that it means he has a circuit for an electric dryer, whether there is one actually plugged into it or not is irrelevant since the whole point of plugs is that they are easy to plug in and unplug.