FAQ
TL;DR: For two 350A welders in a 75 m² workshop, plan ~20 kW; "Estimated about 20kW." Budget for cabling, a switchboard, and verify your power allocation before buying gear. [Elektroda, Strumien swiadomosci swia, #18241155]
Why it matters: This FAQ helps workshop owners planning 400V for welders understand realistic costs, power allocation, and who to hire to stay compliant.
Quick Facts
- Estimated load for the described setup: about 20 kW. [Elektroda, Strumien swiadomosci swia, #18241155]
- Cabling ~PLN 5/m; workshop switchboard ~PLN 800, plus labor. [Elektroda, Strumien swiadomosci swia, #18243220]
- If allocation is too low, apply for new supply conditions with your utility. [Elektroda, brofran, post #18241118]
- Legal business use needs a separate meter and tariff C (costlier than G). [Elektroda, vodiczka, post #18241236]
- Feeding from the house with YAKY cable is often the most economical approach. [Elektroda, Strumien swiadomosci swia, #18241269]
How much will a 400V installation cost for my 75 m b2 workshop?
Expect budget items, not a final price. Cable runs are about PLN 5 per meter. A simple workshop switchboard is around PLN 800. Labor and protection selection add significantly. The final price depends on distance, ground works, and socket count. Get a site quote from a licensed electrician. [Elektroda, Strumien swiadomosci swia, #18243220]
Do I need to apply to ENEA to increase power before adding 400V?
Start by confirming required load and your current allocation. "First, you need to find out what power you need." If your allocation is too low, submit an application to the utility for new supply conditions. Do this before buying equipment. It prevents delays and redesigns. [Elektroda, brofran, post #18241118]
Will ENEA install the sockets and wiring, or do I hire someone?
The utility does not install internal workshop wiring. Hire an electrician with the appropriate qualifications and insurance. Discuss scope, load, socket types, and documentation. Ask for a written quote and completion date. The electrician will also handle tests and as-built diagrams. [Elektroda, opornik7, post #18243265]
Is 20 kW enough to weld with two 350A machines?
One forum assessment puts the requirement at about 20 kW for your scenario. Actual need depends on duty cycle, simultaneous welding, and other tools. Oversize slightly to avoid nuisance trips. Confirm the allocation with your supplier and electrician. Adjust plans if the allocation is below this figure. [Elektroda, Strumien swiadomosci swia, #18241155]
Should I install a separate meter now, or can I feed the workshop from my house?
For private, non-business use, feeding from the house is acceptable. If the workshop becomes a legal business, install a separate meter and move to tariff C. Tariff C is more expensive than tariff G. Plan this change if you expect to register a business later. [Elektroda, vodiczka, post #18241236]
Is it cheaper to run power from my house to the workshop with YAKY cable?
Yes, running a YAKY cable from the house is often economical. This holds even if you must increase your allocated power. Place the cable appropriately and size it for the load. Your electrician will specify the cross-section and route. This was described as profitable versus a separate connection. [Elektroda, Strumien swiadomosci swia, #18241269]
My workshop is 15 m from the house. What would the cable and board cost?
At PLN 5 per meter, a 15 m run costs about PLN 75 for the cable. A basic workshop switchboard is around PLN 800. Labor, trenching, and protection selection are extra. Ask for an all-in quote to avoid surprises. Keep a contingency for unforeseen groundwork issues. [Elektroda, Strumien swiadomosci swia, #18243220]
Can a 230V-only setup handle a 350A MIG welder?
Your current 230V setup did not meet your welding needs. That is why you plan a 400V welder. Choose equipment that matches your planned 400V installation. Share the welder plate with your electrician for sizing. [Elektroda, TomaszNZM, post #18241105]
My house already has three-phase. Does that help?
Yes. In this case, the house already has a three-phase installation. That supports adding 400V circuits in the workshop. Confirm details with your electrician. Extend from the main board to the workshop as designed. [Elektroda, TomaszNZM, post #18243200]
Who sizes the sockets, wire, and protection for welders?
Your licensed electrician does. They will select socket ratings, protection devices, and cable cross-sections. Provide welder specifications and planned simultaneous use. Request documentation and test results after installation. Keep these for future inspections or upgrades. [Elektroda, opornik7, post #18243265]
What are the first steps to get 400V into my workshop?
Follow this simple path:
- Define your load and confirm your current allocation with the supplier.
- Hire a licensed electrician to design and quote the job.
- Install, test, and document the switchboard, cable, and sockets.
"You need to look for an electrician with the appropriate papers and talk to him." [Elektroda, opornik7, post #18243265]
What happens if I try to run two welders on too little power?
Insufficient allocation can halt work and disrupt welding. If available power is too low, submit an application for new supply conditions. Do this before installing expensive gear. It prevents rework and protects your tools. Plan headroom for other workshop loads too. [Elektroda, brofran, post #18241118]
How many 400V sockets should I plan for?
The thread scenario needs three or four 400V sockets. Match socket ratings to your welders and other tools. Group sockets on appropriate circuits as designed by your electrician. Extra spare capacity often pays off later. [Elektroda, TomaszNZM, post #18241105]
