Mike Dolt Enterprises
Mike Dolt Enterprises
User: florida-sparkey, Location: Pinellas Park, Florida
Asked on: Tuesday, April 5, 2011 at 4:16 pm EDT
Answered on: Tuesday, May 14, 2024 at 3:48 am EDT
Question: Hello,Need to "bounce one off the guys"I have a 3ph delta service with an overloaded (by calc) 225 Amp panel. I want to up grade by going to a 400 Amp 3ph meter & feeders, then feeding two panels directly from meter with 2 sets of feeders. # 1 is the original 3ph. # 2 will be a new 150 Amp 1ph to serve 120V loads moved from #1. (Most loads are 1ph, only a/c 3ph.) Both panels will be inside the structure and side by side. I do not want to reinvent the wheel, just remove 120V load from a delta panel.
Feasibility
Your plan to upgrade to a 400 Amp 3-phase service and feed two panels directly from the meter is feasible. However, there are a few important considerations to ensure a safe and code-compliant installation:
Panel Capacity and Load Distribution
The original 225 Amp panel is overloaded and needs to be replaced. The new 400 Amp panel will provide sufficient capacity for the existing and future loads. The 150 Amp 1-phase panel should have enough capacity for the relocated 120V loads.
Conductors and Overcurrent Protection
The feeders from the meter to the panels must be sized appropriately for the panel capacity and the calculated loads. The feeders should be installed in accordance with the National Electrical Code (NEC). Overcurrent protection devices (circuit breakers or fuses) should be installed in both panels to protect the conductors and equipment.
Neutral Connection
Since the original panel is a delta service, it does not have a neutral wire. When you introduce a 1-phase panel, a neutral wire must be provided. The neutral wire should be connected to the neutral bar in the 1-phase panel and grounded at the service entrance.
Load Balancing
It is important to balance the loads between the two panels to prevent overloading either one. Consider the location of the loads and their power requirements when distributing them across the panels.
Grounding
Proper grounding is essential for safety.* The grounding electrode system should be installed in accordance with the NEC and local codes.
Recommended Steps:1. Hire a licensed electrician to perform a load calculation and design the new electrical system.
2. Obtain the necessary permits from the local authority.3. Upgrade the service to 400 Amp 3-phase.
4. Install the new panels and connect them to the meter.5. Move the 120V loads to the 1-phase panel.
6. Inspect and test the new system to ensure it is operating safely and efficiently.By following these guidelines, you can successfully upgrade your electrical system and remove the 120V load from the delta panel. Flag for review