Okay, let's break down your situation and address your questions about the electrical service to your mobile home, focusing on NEC (National Electrical Code) compliance.1. Need for Disconnect B (Within 30 Feet)



Yes, your understanding is generally correct. The NEC requires a readily accessible disconnecting means located within sight and within 30 feet of the mobile home. This is a key safety feature. Think of it as allowing someone to quickly kill all power to the mobile home in an emergency. NEC 550.32(A) Mobile Home Service Equipment

"The service equipment shall be located outside and within sight of the mobile home, or in a readily accessible location nearest the point of entrance of the service conductors into the mobile home. The service equipment shall be permitted to be located elsewhere on the premises, provided that a disconnecting means suitable for use as service equipment is located within sight of and not more than 30 feet from the exterior wall of the mobile home it serves."

Your Setup is Important

The utility company installed a panel with a meter and disconnect (Disconnect A) 250 feet away. This likely qualifies as "elsewhere on the premises." Therefore, you absolutely need a second disconnect (Disconnect B) within 30 feet of the mobile home.

2. Wiring from Disconnect A to Disconnect B



Yes, you need to run a 4-wire feed from Disconnect A to Disconnect B. This is crucial because you are establishing a feeder, not a service, after Disconnect A. What this means

You need two ungrounded (hot) conductors, a grounded (neutral) conductor, and an equipment grounding conductor.

Why 4 wires? To keep the neutral and ground separate within the mobile home. This is a significant safety provision in the NEC.3. Neutral and Ground in Disconnect B



This is VERY IMPORTANT: Neutral and Ground must be kept SEPARATE in Disconnect B. Why? Because after Disconnect A, you're dealing with a feeder. The only place where neutral and ground are bonded (connected) is at the service disconnect (Disconnect A in your case). Bonding them again creates parallel paths for neutral current, which can be dangerous and can cause nuisance tripping of GFCIs and other issues. Wiring in Disconnect B

Connect the two hot wires to the breaker. Connect the neutral wire to the neutral busbar. DO NOT BOND THE NEUTRAL BUSBAR TO THE ENCLOSURE.

Connect the equipment grounding conductor to the ground busbar. Bond the ground busbar to the metal enclosure of Disconnect B.4. Grounding Rod for Disconnect B



Probably NOT Required. Generally speaking, you don't need a separate grounding electrode system (ground rods) at a subpanel/disconnect like Disconnect B. The grounding electrode system at Disconnect A is sufficient, and the equipment grounding conductor in the feeder (the wire you run between Disconnect A and B) provides the necessary path back to the service grounding system.

Exceptions/Things to Consider



Check with your local inspector. Sometimes local codes or interpretations might vary, especially in situations that aren't straightforward.

If Disconnect B is in a separate building

If Disconnect B were mounted on a shed that is a separate building, the rules would be different. But since it's near the mobile home, and you're running a 4-wire feeder, you most likely do not need a ground rod at Disconnect B.

Summary and Best Practices


Disconnect B is Required

Place it within 30 feet of the mobile home.2.

Run 4 Wires

Hot-Hot-Neutral-Ground from Disconnect A to Disconnect B. Size the conductors appropriately for the 200A service.3.

Separate Neutral and Ground in Disconnect B

Very important!4.

Probably No Ground Rod

Most likely not needed at Disconnect B; consult local inspector.5.

Proper Wire Sizing and Conduit

Make sure all wiring is sized correctly for the 200A service and is installed in appropriate conduit (e.g., PVC or rigid metal conduit).6.

Licensed Electrician is Highly Recommended

This project involves potentially dangerous high voltage. It is always best to consult a qualified licensed electrician.

Disclaimer: I am an AI chatbot and cannot provide professional electrical advice. This information is for general guidance only. Always consult with a qualified licensed electrician and adhere to all applicable local codes and regulations. Incorrect wiring can be dangerous and even deadly. Flag for review