Article 250.140 of the National Electrical Code (NEC) provides guidance on grounding a range with a 4-wire cord where an equipment grounding conductor is not present in the circuit

NEC 250.140(C): Appliances Other Than Fixed Cooking Appliances.

>For appliances other than fixed cooking appliances, the equipment grounding conductor shall terminate at the equipment grounding terminal, bar, or other means provided for ground connection.

Application to 4-Wire Ranges

In the case of a 4-wire range, the NEC does not provide specific instructions for connecting the fourth wire (neutral) when an equipment grounding conductor is not present. However, the following steps are typically followed:1.

Identify the ungrounded conductors

Since you have two "hots", these are your ungrounded conductors.2.

Connect the ungrounded conductors to the range terminals

The two ungrounded conductors should be connected to the corresponding terminals on the range (usually labeled "L1" and "L2").3.

Bond the neutral conductor to the range chassis

The neutral conductor (white wire) should be bonded to the metal chassis of the range using a jumper wire. This connection provides a path for fault current to return to the source, ensuring the range is properly grounded.4.

Identify the grounding terminal

The range may have a grounding terminal marked with a green screw or a "grounding lug".5.

Install a grounding conductor (optional)

Although not required by the NEC, it is recommended to install a grounding conductor from the grounding terminal to a suitable grounding point (such as the cold water pipe or the grounding electrode system). This additional grounding connection provides enhanced safety in case of a fault.

Note: It is important to consult local building codes and regulations, as they may have additional requirements or variations on these guidelines. Flag for review