Flipper installed a new 4-wire NEMA 14-30 dryer receptacle to 'update' the laundry, but the existing cable in the wall is 10-2 NM with ground from the 1990s.

This installation violates the National Electrical Code (NEC) and creates a serious safety hazard.

The Core Problem

The existing 10/2 NM cable only has three conductors: two hot wires (black/red), one neutral (white), and a ground (bare). A NEMA 14-30R requires four separate conductors - two hots, one neutral, and one equipment grounding conductor (EGC).

What's Wrong

1. Improper Neutral-Ground Bonding: By jumping from the neutral terminal to the ground terminal, you've created a parallel path for neutral current to flow on the equipment grounding conductor. This violates NEC 250.142(2) and 250.146, which prohibit using the grounding conductor as a neutral return path.

1. Overloaded Ground Wire: The bare ground wire is now carrying neutral current in addition to any fault current. This can cause the ground wire to overheat, especially since it's sized for fault current only, not continuous neutral load.

1. Misleading "Update": This isn't a proper 4-wire installation. The cable itself lacks the required fourth conductor.

The Correct Fix

Replace the 10/2 NM cable with 10/3 NM with ground (four conductors: black, red, white, bare). This provides the proper separate neutral and ground paths required by NEC 250.146 for 120/240V appliances.

This should be corrected immediately - the current setup can cause overheating, electrical fires, and creates a shock hazard. A licensed electrician should handle the cable replacement.

This is a Code violation and a shock hazard. You have created a "bootleg ground" (NEC 250.142(B)).

What’s wrong:

1. No Equipment Grounding Conductor (EGC): 10-2 NM has only two current-carrying conductors (black/white) and a bare ground. The bare wire is the EGC. It must land on the receptacle’s ground terminal (green screw) only.
2. Neutral ≠ Ground: The dryer requires a dedicated neutral (white) for 120V controls/motor and a separate EGC for the frame. Your jumper bonds the dryer frame to the neutral current path.
3. Shock Hazard: If the service neutral opens upstream, the dryer frame becomes energized at 120V via the motor/control load. Anyone touching the dryer and a grounded surface (washer, pipe, floor) gets shocked.
4. Objectionable Current: Normal neutral return current now flows on the dryer frame and the bare EGC wire (NEC 250.6(A)).

Legal Fixes (NEC 400.9(B)(2), 250.140):

• Option A (Correct): Run new 10-3 NM-B (or 10-3 UF/MC) with dedicated neutral + EGC.
• Option B (Existing Cable Only): Re-install a 3-wire NEMA 10-30R receptacle. Connect: Black→X, White→Y (mark white with black/red tape at both ends), Bare→Ground terminal. Remove the jumper. Supply a 3-prong cord. On the dryer, move the factory ground strap from neutral terminal to the frame ground screw per manufacturer instructions. This is legal only for existing installations (NEC 250.140 Exception).

Do not use the 4-wire receptacle with 10-2 cable. Pull the receptacle, cap the neutral terminal, install the 10-30R, and configure the dryer cord correctly.