Splitting 230V and 115V on device entrance

Bertsbolts

Member
Location
Florida
Occupation
Production Engineer - Heating, Cooling and Electrical Control Systems
Hi folks,
Just a bit of windup here. We have a boiler package unit that requires a 115/120VAC power source. In some of our packages we have an option for a 230VAC boiler pump. To accomplish this, we currently supply the boiler with two different power sources. This bugs me for various reasons.
My solution is to provide the single power source of 230VAC 1ph to the boiler, then split off the 115/120 from that connection.
Pictorial: 1717087579374.png

Fuses protect the various components after the voltage split.
This single source splitter would be inside its own enclosure inside the boiler, with the pigtails on output going where they need to.
My Question is:
Is this a doable option that keeps the wiring neater in the enclosure with the control board, electrically sound, and is it within safety concerns?
 

Besoeker3

Senior Member
Location
UK
Occupation
Retired Electrical Engineer
My solution is to provide the single power source of 230VAC 1ph to the boiler, then split off the 115/120 from that connection.
Pictorial:
1717087579374.png
For UK and EU we have just 230Vac. It's simpler.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
I don't have a major issue with the idea but if the instructions the manufacturer supplies tells you to use two separate supplies I would be inclined to do so. There might be some non-obvious reason for doing so.
 

Bertsbolts

Member
Location
Florida
Occupation
Production Engineer - Heating, Cooling and Electrical Control Systems
I don't have a major issue with the idea but if the instructions the manufacturer supplies tells you to use two separate supplies I would be inclined to do so. There might be some non-obvious reason for doing so.
Instructions from boiler manufacturer are non existent for this action. We do work closely with the mfr. on any mods we want to do. Mostly to maintain warranty. In this case, they were ok with the two sources thing, relay mounted internally. I am concerned about tech safety. Having to ensure two separate power sources are off before serving thing. They are marked with a label for that, but experience tells me some don't pay attention
My reason for reaching out here is because a bean counter wants to argue that it won't work right. ☺ So backup was required. ☺ Thanks
 

Jraef

Moderator, OTD
Staff member
Location
San Francisco Bay Area, CA, USA
Occupation
Electrical Engineer
The caveat would be that the 240V source would HAVE TO include the neutral. If the source is a 230V 3 phase Delta system, it may not. So you would have to include SPECIFIC instructions to that effect. An alternative would be to have a single 240V input and provide a small(ish) 120V transformer inside to derive the 120V control power.
 

petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
Instructions from boiler manufacturer are non existent for this action. We do work closely with the mfr. on any mods we want to do. Mostly to maintain warranty. In this case, they were ok with the two sources thing, relay mounted internally. I am concerned about tech safety. Having to ensure two separate power sources are off before serving thing. They are marked with a label for that, but experience tells me some don't pay attention
My reason for reaching out here is because a bean counter wants to argue that it won't work right. ☺ So backup was required. ☺ Thanks
If the techs can't or won't follow the rules and shut off power and thus work live, that is a major management and supervision failure and some of those heads should roll.
 

norcal

Senior Member
For UK and EU we have just 230Vac. It's simpler.
Yeah but when your end of the world was just beginning to be wired, there was a clean slate so AEG chose 220V, Edison's 110V was already a legacy system & Tesla & Westinghouse had to match it. Big difference & agree it's simpler to deal with 400/230V.
 

Besoeker3

Senior Member
Location
UK
Occupation
Retired Electrical Engineer
Yeah but when your end of the world was just beginning to be wired,


The first electric lights for a house in the UK were lit in 1878

Thomas Edison​

In 1879, the American inventor Thomas Edison was finally able to produce a reliable, long-lasting electric light bulb in his laboratory.

So, not much different.
 

CoolWill

Senior Member
Location
Alabama
Occupation
Electrical Contractor
The first electric lights for a house in the UK were lit in 1878

Thomas Edison​

In 1879, the American inventor Thomas Edison was finally able to produce a reliable, long-lasting electric light bulb in his laboratory.

So, not much different.
You're pretty hung up on this, huh?
 

kwired

Electron manager
Location
NE Nebraska
I don't have a major issue with the idea but if the instructions the manufacturer supplies tells you to use two separate supplies I would be inclined to do so. There might be some non-obvious reason for doing so.
Run a feeder to a 4 or 6 circuit panel near the equipment and then run your two circuits from there? Also takes care of your disconnecting means requirements if the feeder originates away from this equipment.
 

Besoeker3

Senior Member
Location
UK
Occupation
Retired Electrical Engineer
You already live in the UK, the voltage is 240. What is there to prefer?
It is 230Vac for UK and for the European union. The USA has several different voltages like 240V and 120V.
This is for residential.
 

CoolWill

Senior Member
Location
Alabama
Occupation
Electrical Contractor
It is 230Vac for UK and for the European union. The USA has several different voltages like 240V and 120V.
This is for residential.
What I mean is, you have a single voltage supply, unlike our split voltage supply. You said you prefer a simpler approach, but there is no preference if there is no choice. Even if you preferred it another way, you don't have a choice. Outside of that, it doesn't matter at all because the OP is in the US and the equipment he has takes both 120 and 240 volts, so your preference for simpler systems is immaterial to the topic at hand.
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
What I mean is, you have a single voltage supply, unlike our split voltage supply. You said you prefer a simpler approach, but there is no preference if there is no choice. Even if you preferred it another way, you don't have a choice. Outside of that, it doesn't matter at all because the OP is in the US and the equipment he has takes both 120 and 240 volts, so your preference for simpler systems is immaterial to the topic at hand.
Yeah.jpg
 

tortuga

Code Historian
Location
Oregon
Occupation
Electrical Design
Hi folks,
Just a bit of windup here. We have a boiler package unit that requires a 115/120VAC power source. In some of our packages we have an option for a 230VAC boiler pump. To accomplish this, we currently supply the boiler with two different power sources. This bugs me for various reasons.
My solution is to provide the single power source of 230VAC 1ph to the boiler, then split off the 115/120 from that connection.
Pictorial: View attachment 2571869

Fuses protect the various components after the voltage split.
This single source splitter would be inside its own enclosure inside the boiler, with the pigtails on output going where they need to.
My Question is:
Is this a doable option that keeps the wiring neater in the enclosure with the control board, electrically sound, and is it within safety concerns?
One problem I see is if the boiler is on a 240 delta system the installer might want to balance the load on the delta by placing the Boiler pump power on the A&B or the C&B phases that do not have 120V to ground.
 

Besoeker3

Senior Member
Location
UK
Occupation
Retired Electrical Engineer
What I mean is, you have a single voltage supply, unlike our split voltage supply. You said you prefer a simpler approach, but there is no preference if there is no choice. Even if you preferred it another way, you don't have a choice. Outside of that, it doesn't matter at all because the OP is in the US and the equipment he has takes both 120 and 240 volts, so your preference for simpler systems is immaterial to the topic at hand.
My point was the simple approach for residential. My field is industrial and particularly variable speed drives.
 
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