Inrush Current Limiters and Soft Starts

[WA2LTD]

Inrush Current Limiters and Soft Starts
Thomas G. Siglin – WA2LTD

Part3... Including schematic and parts list

The previous article concluded with a semi-automatic inrush current limiter using an AC relay design. That accomplished the basic task of reducing the inrush current but did little for a true soft start because the delay from power on to relay bypassing the series dropping resistor was short. If our application was equipment needing “fast-on” power such as a piece of digital equipment or a power supply for a modern solid state radio, it fits well. For the rest of us with tube type analog equipment, more warm-up time is better.

Let’s build a model using a DC relay with a RC timing network to delay energizing the relay. A DC relay won’t chatter and is easy to build a delay for. The resistor/capacitor values will set the delay time, but they must be designed around the relay we choose. The relay used is an NTE R10-11010-110 DPDT, 12 Amp. (It actually says 110Volts DC but that is immaterial to the project) The DPDT contacts will be wired in parallel to increase the current/power handling of this part.

While many relay/capacitor/resistor combinations are possible, this article uses:

120 Volt DC coil (~10,000 Ohm resistance)
1000 uf timing capacitor
2700 Ohm charging resistor

If you use radically different components i.e. 24 Volt relay your R2 charging resistor value will likely change along with its dissipation (it will get hotter). Your capacitor voltage will be lower but may require higher capacity value i.e. 2000 uf. for the proper time delay.

Because this is a DC circuit, we also need to convert the AC Voltage. A simple method is to use a single (1N4007 or equal) diode to form a half wave rectifier circuit. Keep in mind that polarity of the capacitor and diode is important. Capacitors seem to be marked on the negative terminal (-) more often than the positive (+) these days. The diode’s cathode, marked by a band around the body is the end towards the positive (+) capacitor connection at the relay. In the test circuit, the relay pulled in at 65 Volts, with the final voltage at the relay settling at 80 Volts, there’s enough margin to ensure proper circuit function.

With the values suggested, there is a delay of ten seconds, enough time to give the tube filaments a chance to warm up under reduced voltage and lower inrush current levels. A check of a cold 3-500 tube filament indicated a resistance of .3 Ohms for a calculated current of 83 Amps. When compared to the running current of 15 Amps, you’ll appreciate the potential for increased tube life by using a soft start.

To use this model, leave the radio equipment turned on and control the power from the ICL on/off switch.

Note: switch and outlet connections below are drawn with screws to emphasize their connection style.

http://geocities.com/tsiglin/DC_Resistor_Limiter-Soft.gif

PARTS LIST
# Enclosure (deep 4X4 utility box w/ cover and suitable cord clamp)
# 1 Power cord (suitable for the power requirements)
# 1 Outlet (to fit cover plate)
# C1 1000 uf., 100 Volt electrolytic capacitor
# D1 1N4007 Diode #
# F1 3 Amp fuse and holder (or thermo-fuse positioned to prevent overheating of R1)
# R1 10 or 20 Ohm 20-25 Watt resistor. (Use a 20 Ohm for lighter loads and
# # # # softer action. For higher power equipment, a 10 Ohm is suitable) # #
# R2 2700 Ohm, 1 Watt resistor
# Rly1 120 Volt DC relay (NTE, R10-11010-110 DPDT, 12 Amp or equal)
# S1 Toggle switch (to fit cover plate)

In the next (and last) article of this series, part 4, the circuit above will be modified to use an NTC thermister for a nice “ramp-up” to full voltage as opposed to the somewhat step start function of this unit

For additional info, please eMail: tsiglin@SIGTOMICS.com

[kb7uxe]

Can this be used for 220V by moving R2 connection from white to Green ?

[WA7PRC]

KB7UXE: "Can this be used for 220V by moving R2 connection from white to Green?"

A single-pole 240V circuit would have L1 (Black), L2 (Red), Ground (Green/Bare), and sometimes also Neutral (White) -- if there are 120V load(s). In your example, you could probably get away with it but, for safety, it's best to use a 4-wire connector to separate Ground from Neutral. #McMaster-Carr (http://www.mcmaster.com/) has good information online to help choose a suitable connector...

NEMA Straight-Blade connectors: http://tinyurl.com/yy7g3o
NEMA Turn-Lock connectors: http://tinyurl.com/y23lwp

For a typical 1.5 KW output HF amplifier, you're looking at around 2.5KW input power-- about 10.5A @ 240V. #You'd want to run at least a 15A source to it. #The NEMA 14-30 (250/125V,30A) connector is the smallest in a straight-blade 4-wire type. A suitable turn-lock would be the L14-20 (125/250V,20A). Theoretically, because my SB220 has a 120VAC cooling fan, it should be using a 4-wire cord & connector (and it will, when I recommission it).

73,
Bryan WA7PRC

[N9OH]

Good articles! #Back when I purchased my 2nd hf amp I considered getting an inrush current protector to save on tube life... but decided against it at the time due to the cost. #When this series is complete it may become my next project: to build one myself.

[kb7uxe]

ok, here's a better mouse trap..
This should work for 220..
I would assume the relay may have a different part number,
also note F1=F2, and R1= R3...

If the coil is the same impedance, the bleeder resistor and cap should work the same. ..

to the designer of the orginal ckt, pls confirm this will work??
tnx, Dan. kb7uxe.

[kb7uxe]

duuuhhhhh..
Corrected drawing..pay not attention to the previous drawing.. geeeze,, must be too early..
8-)

[w6em]

Quote[/b] (kb7uxe @ Jan. 05 2007,11:23)]duuuhhhhh..
Corrected drawing.. geeeze,, must be too early..
8-)
I hate to burst your bubble, but, a "white" is not a "green". #The grounding conductor is not to be confused with a neutral, which does carry current and therefore can become elevated above ground potential.

Forget the neutral. #Use a 220V DC or AC coil relay (works with DC too) or just recalculate your dropping resistor for 230V input to achieve what voltage you want to pick up the relay.

A standard 220V NEMA 15A receptacle is two hotlegs, red and black, and a grounding conductor, a green wire. #Notice the screw colors, one will be green for ground.

Not to be too picky with your design, but if the relay coil should open, the capacitor will see full rectified input peak voltage. #For 115V applications, I'd use a 250WVDC capacitor. #For 230V applications, a 400WVDC capacitor.

Now, got to ask this pesky question: #Why did you insist on a 1N4007 diode? #A 1N4003, 200PIV, or a 1N4004, 400PIV would be just fine for both 115V and 230V applications.

Also, you're cutting the rating of the 2700 Ohm resistor kinda close. #You might smell it cooking. #Its going to dissipate about 3/4 of a Watt continuously. #Better to use at least a 2W and preferably a 5W for the 115 V application.

Now, a 10 Ohm series resistor at 25 Watts is a bit overkill. #Why? #Well, since the relay will bypass it in a second or two, the energy dissipated is miniscule. #Same goes for the 20 Ohm. #Your fuse will blow quickly for a short circuit on the load side and is a good idea. #However, if your line voltage drops low enough such that the relay doesn't pick up, it won't save the resistor.
A thermal fuse might, though.


73,

[w6em]

Quote[/b] (WA7PRC @ Jan. 05 2007,03:33)]KB7UXE: "Can this be used for 220V by moving R2 connection from white to Green?"

A single-pole 240V circuit would have L1 (Black), L2 (Red), Ground (Green/Bare), and sometimes also Neutral (White) -- if there are 120V load(s). In your example, you could probably get away with it but, for safety, it's best to use a 4-wire connector to separate Ground from Neutral. #McMaster-Carr (http://www.mcmaster.com/) has good information online to help choose a suitable connector...

NEMA Straight-Blade connectors: http://tinyurl.com/yy7g3o
NEMA Turn-Lock connectors: http://tinyurl.com/y23lwp

For a typical 1.5 KW output HF amplifier, you're looking at around 2.5KW input power-- about 10.5A @ 240V. #You'd want to run at least a 15A source to it. #The NEMA 14-30 (250/125V,30A) connector is the smallest in a straight-blade 4-wire type. A suitable turn-lock would be the L14-20 (125/250V,20A). Theoretically, because my SB220 has a 120VAC cooling fan, it should be using a 4-wire cord & connector (and it will, when I recommission it).

73,
Bryan WA7PRC
High, Brian. #Your SB-220 probably has a tapped primary on its transformer or some such to get the 115V needed for the small fan. #I have a high current switching supply that uses a small auto transformer for just that purpose.

It is really unusual to see a 230V 15A or 20A branch circuit with a neutral, except maybe from a small generator. #Most all appliances just use the two hot legs and the grounding conductor.

When wiring my shop, I had some extra 12-3, so I capped off the neutral in the box and panel, but didn't use it. #My linear and step down transformer don't need a neutral and, of course, I've got several 115V 20A branch circuits as well.

Also, its a code infraction to use a higher rated receptacle than the rating of the branch circuit and its associated circuit breaker. #The reason: #Easy to mistakenly plug in an appliance requiring, say, 24 Amps continous current.

If its a 15A branch circuit, use only a 15A UL-listed receptacle. #Same for 20A circuits.

There is an exception for 20A 115V circuits. #You can use 15A receptacles since they are rated for 20A pass through.

73,

[kb7uxe]

1st, this design was presented by WA2LTD..
I simply tried to modify his design to work for my 220V ckt.
And I am awaiting input from orignal designer to confirm if this drawing will work.

2ed, in the panels around here, green and white are always connected together to ground.
I guess if it aint right, some inspectors may need their glasses changed. ..
I worked on a fire truck that kept burning up a $3000 inverter charger..
I found the green and white tagged together to ground. ( ok for house wire, but in the use of an inverter,
very critical to isolate white and green.

This could be differnt in 3phase, but then again, I aint no lectrition...
8-)

Dan.

[w6em]

Quote[/b] (kb7uxe @ Jan. 05 2007,12:04)]1st, this design was presented by WA2LTD..
I simply tried to modify his design to work for my 220V ckt. #
And I am awaiting input from orignal designer to confirm if this drawing will work.

2ed, in the panels around here, green and white are always connected together to ground.
I guess if it aint right, #some inspectors may need their glasses changed. ..
I worked on a fire truck that kept burning up a $3000 inverter charger..
I found the green and white tagged together to ground. ( ok for house wire, but in the use of an inverter,
very critical to isolate white and green.

This could be differnt in 3phase, but then again, #I aint no lectrition...
8-)

Dan.
Hello, Dan. #Well, a neutral is designed to carry return current. #As such, due to return current and impedance between the bonding point of neutral and ground and a remote point on the neutral can result in considerable voltage rise. #The neutral bus at the panel is tied or bonded to the grounding means and the equipment grounding bus at the panel. #If it is the service entrance panel. #If it is a remote panel, like a sub-panel, then they are to be kept isolated at that point.

As to your experience with an inverter, well, I'd have to look inside to see how the neutral is derived. #Chances are, it had significant imbalance and your connecting them together externally caused a problem, which, it should not have.

Stay away from thinking that the grounding conductor can carry return current. #It can hurt you (or worse) when you least expect it if you try to use it like that.

Good luck with your project. #And, I've had a little more education and experience in power than the average electrician. #:-)

As to three phase, if the loads are connected line to line, then no neutral current. Line to neutral, well, unless balanced at all locations, there will be neutral current. Neutrals on three-phase systems are bonded to the grounding conductor and bus at the service entrance also.

73,

[WA2LTD]

Hi everyone,

Thanks for the comments on the ICL and soft start series. I hope the series has been insighful with the various designs, but the ultimate goal is a unit that will be presented in part 4. The series will conclude with a true soft start design and will include a #240 Volt version as well.

Notes on part 3:

The R2 resistor should not be connected to the green saftey ground to modify the unit for 240 Volts. Ground is not supposed or intended to carry operating current. #It's not that it won't work, it's the rules of the game... If you used a 4 wire cord set, your connection to neutral is allowed, and would be fine for a true 240 Volt application. (but I wouldn't carry the neutral to the outlet socket... that way it would serve as a reminder this is not a split 240 circuit)

If the application is for true 240 Volt equipment, meaning no neutral wire is needed because of power supply design, then I feel the easiest method to up-scale this design to 240 Volts is simply increase the R2 resistor value (~15 K Ohms and power handling capability (~ 3 Watts). The 240 Volt cord set wire is black(hot, line 1), green(saftey ground) and RED(hot, line 2). Install the appropiate socket for your instalation. #

For equipment that is using a split, 240 Volts, I would mirror the R1 fused circuit and use a second set of relay contacts to bypass R1. An alternate approach would be two relays, perhaps in series if they have similar characteristics, with each relay's contacts taking care of one bypass resistor (R1). The higher value series relay charging resistor or a higher voltage relay coil makes the project a bit easier but don't forget to up-scale the timing capacitor voltage rating too. While you can't go wrong using a capacitor greater than the peak value of the line operating voltage, they are expensive.

One reason I would not put an overly big wattage resistor at R2 is saftey. Resistors can be great fuses when sized appropiately. If the relay circuit has a open relay coil, shorted diode or capacitor fault, the resistor will open. With low wattage resistors the fault current is kept to a few Watts.

For the 120 Volt design, the 2700 Ohm resistor indicated 30 Volts (Fluke RMS DVM) across it under operating conditions. That calculates to .33 Watts dissipation for this half wave design.
#
I may have caused some confusion or a side ways glance with the particular components in this design, but consider that I built the units with parts on hand. So while a lower PIV diode will work fine, I couldn't go wrong with a 1N4007. #The R1 power resistor is a carry over from previous articles and for consistantcy is re-used here. You are welcome to size the individual components for the equipment you are working with.

73,
Tom - WA2LTD

[w6em]

Quote[/b] (WA2LTD @ Jan. 05 2007,19:58)]One reason I would not put an overly big wattage resistor at R2 is saftey. Resistors can be great fuses when sized appropiately. If the relay circuit has a open relay coil, shorted diode or capacitor fault, the resistor will open. With low wattage resistors the fault current is kept to a few Watts.

For the 120 Volt design, the 2700 Ohm resistor indicated 30 Volts (Fluke RMS DVM) across it under operating conditions. That calculates to .33 Watts dissipation for this half wave design.
#
Hello, Tom. Well, as to the R2 resistor wattage, I had assumed you used a line voltage toward the high end of the range, around 125V. Up to 126 is permitted within NEMA utilization standards. On that basis, the resistor would be a bit warm.(46 volts drop across the resistor, using your 80V coil voltage) But, at 110V, not a problem. Based on what you've shared, (30V resistor drop and 80V across the coil) I calculated the coil resistance, and as a result, the 2700 Ohm resistor at most will dissipate just under a half Watt at the 125V level, so that should be OK. Not knowing what your line voltage was was a key missing ingredient.

With respect to it acting like a fuse if the coil or capacitor were to short, well, yes, but probably not fast enough to prevent capacitor explosion. When capacitor dielectrics start to puncture, often times internal pressure builds, followed by an explosion, if not vented. The amount of energy involved usually isn't a lot until ultimate destruction. The difference in cost between a 1000uF 100WVDC capacitor and a 250WVDC capacitor can't be all that much.

I like your idea of a thermal fuse for the series inrush resistor. That way, if the relay fails to close for whatever reason, you won't have a smoke generator :0-)
Plus, heat around PVC wire insulation can have nasty corrosive results as well.



73,

[WA7PRC]

Quote[/b] (KB7UXE @ Jan. 05 2007,20:44)]Can this be used for 220V by moving R2 connection from white to Green?

Quote[/b] (WA7PRC @ Jan. 06 2007,01:33)]A single-pole 240V circuit would have L1 (Black), L2 (Red), Ground (Green/Bare), and sometimes also Neutral (White) -- if there are 120V load(s). In your example, you could probably get away with it but, for safety, it's best to use a 4-wire connector to separate Ground from Neutral. #McMaster-Carr (http://www.mcmaster.com/) has good information online to help choose a suitable connector...

NEMA Straight-Blade connectors: http://tinyurl.com/yy7g3o
NEMA Turn-Lock connectors: http://tinyurl.com/y23lwp

For a typical 1.5 KW output HF amplifier, you're looking at around 2.5KW input power-- about 10.5A @ 240V. #You'd want to run at least a 15A source to it. #The NEMA 14-30 (250/125V,30A) connector is the smallest in a straight-blade 4-wire type. A suitable turn-lock would be the L14-20 (125/250V,20A). Theoretically, because my SB220 has a 120VAC cooling fan, it should be using a 4-wire cord & connector (and it will, when I recommission it).

73,
Bryan WA7PRC

Quote[/b] (W6EM @ Jan. 06 2007,09:59)]High, Brian. #Your SB-220 probably has a tapped primary on its transformer or some such to get the 115V needed for the small fan.
The SB220 uses dual-primary plate and filament transformers. #The fan is across one pair of windings.

Quote[/b] (W6EM @ Jan. 06 2007,09:59)]I have a high current switching supply that uses a small auto transformer for just that purpose.
That would eliminate the need for a Neutral return to the source. #It's still not a bad idea.

Quote[/b] (W6EM @ Jan. 06 2007,09:59)]It is really unusual to see a 230V 15A or 20A branch circuit with a neutral, except maybe from a small generator. #Most all appliances just use the two hot legs and the grounding conductor.
A Neutral return used to be unusual (but not unheard-of). #As I understand it, NEC now requires it.

Quote[/b] (W6EM @ Jan. 06 2007,09:59)]When wiring my shop, I had some extra 12-3, so I capped off the neutral in the box and panel, but didn't use it. #My linear and step down transformer don't need a neutral and, of course, I've got several 115V 20A branch circuits as well.

Also, its a code infraction to use a higher rated receptacle than the rating of the branch circuit and its associated circuit breaker. #The reason: #Easy to mistakenly plug in an appliance requiring, say, 24 Amps continous current. #If its a 15A branch circuit, use only a 15A UL-listed receptacle. #Same for 20A circuits.
Though it may be a code infraction, it seems reasonable to use connectors and/or wiring that are rated higher than the fuse/breaker.

Quote[/b] (W6EM @ Jan. 06 2007,09:59)]There is an exception for 20A 115V circuits. #You can use 15A receptacles since they are rated for 20A pass through.
I'd rather have the fuse/breaker do the current limiting, rather than the connector.

Like others responding prior to this post, I didn't catch a big safety concern. In all the examples, there are connections that bypass the fuse(s). #The <span style='color:red'>first and only</span> thing the incoming source should connect to, is/are the fuse(s). #

73,
Bryan WA7PRC

[w6em]

duped post deleted

[w6em]

Quote[/b] ]A Neutral return used to be unusual (but not unheard-of). #As I understand it, NEC now requires it.

Brian: #Sorry, but that isn't true. #Why not? #Think about it for a second. #If a 230V transformer primary were center tapped and both hot legs and a neutral were connected, and the 230V current was 12A, and served by a 15A, 230V branch circuit, what would happen if one of the legs of the power switch opened? #Bingo, 24A of circuit current and a tripped breaker. #You hope.

Quote[/b] ]
Though it may be a code infraction, it seems reasonable to use connectors and/or wiring that are rated higher than the fuse/breaker.

Brian: #Larger wire is permitted. #Larger receptacles are not. #Something about protecting the unknowing public from unintentionally overloading a branch circuit by plugging in something too big.

Quote[/b] ]I'd rather have the fuse/breaker do the current limiting, rather than the connector.

You do as you choose, just don't think your insurance company will pay off like a slot machine if you fill your house with NEC infractions and your house catches fire..


Quote[/b] ]Like others responding prior to this post, I didn't catch a big safety concern. In all the examples, there are connections that bypass the fuse(s). #The <span style='color:red'>first and only</span> thing the incoming source should connect to, is/are the fuse(s).

No, no big safety concerns. #Its well thought and only a couple of minor suggestions. #Your response, here, is a bit weird. #You say there are connections that bypass the fuse, yet you go on to say that that the only thing the incoming source should connect to is a fuse.

A bit confusing, Brian. #The equipment is fused. #The coil is fed via a relatively high ohmic value resistor. #Oh, well.

Following the NEC, Brian, is always a good idea.


73,

[WA7PRC]

Lee,

Though I stand on what I said, I don't want to get into a protracted debate. #We've veered off-topic long enough.

73,
Bryan WA7PRC

[n5kbp]

A good source for relays is the control panels from broken electric ranges. I used 2 SPST rated for 30 amps @ 240Vac to put one in my old SB-200 a few years ago. Check with your local appliance repair shop for the old control boards.

Marty
N5KBP

[kc4wdn]

Marty!
I was wandering if part 1 and 2 of this post was ava. Thanks for the info on the relays.

John Dance
KC4WDN

[WA2LTD]

Quote[/b] (kc4wdn @ Jan. 08 2007,09:20)]Marty!
I was wandering if part 1 and 2 of this post was ava. Thanks for the info on the relays.

John Dance
KC4WDN
Hi John,

On QRZ, look to the right and find the "Older News". At the bottom of that column find "more news.

Part 1 and part 2 are among those articles. If you
need the schematics and pictures, please email me
tsiglin@sigtomics.com

73,
Tom - WA2LTD

[KE4FES]

http://www.qrz.com/iB_html/non-cgi/emoticons/tounge.gif In dual voltage 3 wire systems. The neutral circuit serves to carry any unbalanced current and provides for the lower voltage termination. IT IS NOT A GROUND WIRE / CIRCUIT

CHARLIE

[k4wh]

A little off topic, but it has been touched on. 240 volt wiring. I a new house just built, the electrician ran a 240 volt 40 amp line to the radio room. He used a four wire Dryer outlet, red, black, white, ground ( copper ). I have never had to wire an amp for a four wire outlet. All the amps I have used have been a three wire plug, to a three wire outlet. In the past I have used 30 amp ( three wire ) twist lock outlets and plugs rated for 30 amps, 240 volts. I have been told to now use just the red and black, as hot leads, ( to the amp ), and the white as the ground ( to the amp ). I was told that the white and the copper ground, are bonded together at the box. Pulled the front of the panel off, and sure enough, on all the 220/ 240 volt circuits, the white and copper are locked and bonded to the same buss, and on all those circuits , the red and black wires are fed to the breakers. On the 120 volt runs, the breakers are fed with a white/neutral and black to each side.

The amp, and Alpha 99, is supplied with a power cord wired as, white/black/green.

I am assuming, from what I have been told, that I should now wire the Alpha as follows: Black to Black, White lead on Alpha now goes the Red lead on the wall outlet, and the Green ( ground ) wire on the Alpha should got to the White on the wall outlet ( or to the green, as some people have said it makes no difference since both are bonded together ).

Better to ask first. Thanks for any help. It use to be so simple.

[w6em]

K4WH:

Your electrician friend did you a favor, of sorts. #But, left you with a bit of confusion.

First off, DO NOT EVER connect what was intended to be an appliance grounding conductor to the neutral of a branch circuit. #Why? #Because a neutral bus, separate from the bonding point on your service entrance (where the neutral and ground are tied together-the ONLY place) can be elevated substantially. #How? #Neutrals carry return current from the split 230V source. #As such, there can be no guarantee that, due to unbalanced 115V loading, that all neutrals will always be at O volts. #Or, in other words, the same as your grounding means. #Just think about it for a second. #Sure, in the average house, where there are no sub-panels, remote from the main panel, it doesn't really apply unless, somehow, neutrals are cross connected (a no-no).

But, as in your case, if you were to install a small 60A subpanel, with 40A main breaker or molded case switch, the neutral within that subpanel, by NEC requirement, cannot be connected to the grounding conductor. #And, the reason for that is to, at all times and locations, keep all return currents off of the grounding conductor (the green wire) and thus keep it at 0 volts. #Or, as close to 0 volts as is possible. #So, you would, to the extent you had several 15 or 20A 120V branch circuits from that subpanel, have an elevated neutral bus connected to all of the white wires emanating from it if not all 115V loads were perfectly balanced across both hot legs.

So, your amp's appliance cord black and white should be connected to red and black, and the green wire connected to only the branch circuit grounding conductor (green or bare). #It would also be a good idea to use some red electrical tape to wrap on the white conductor inside the amp and inside the plug, to identify it as another hot leg.

But, wait, I recommended doing that since your amp is rated for either a 15A or 20A 230V branch circuit. #It should not be plugged directly into a 40A branch circuit receptacle.

To comply with the National Electric Code (NEC), you could either go back to your panel, and replace the 40A breaker with either a 20A or a 15A and then replace the 40A receptacle with either a 20A or 15A 230V receptacle, accordingly, without using the neutral at all. #Just cap it off with a wire nut). #Or, you could use the capability available by making up a sub panel box and several branch circuits from it. #Say, one 230V 20A, and a couple 115V 20A circuits. #Of course, each circuit will need its own breaker, boxes and receptacles. #And, you will need a 40A main breaker or molded case switch for the sub panel and some 40A 4 conductor cord and the plug......

Not a bad idea to have something like that for shack power. #That way, you can shut off everything from one point, close at hand.

I took the more expensive route for my shack, or it seems that way, by running a 20A 230V circuit and a 20A 115V circuit all the way from a subpanel on the other side of the house. #Well, not exactly. #I had the good fortune to have two surplus 30A 'home runs' of romex left from the removal of an electric water heater and heat pump auxiliary resistance heater. #That cut down the cost of that extra "golden conductor" (12-2 romex) significantly.


73,