Devices without neutrals

[hillbilly1]

Most 3 phase loads do not use a neutral.

I hate it when they do, I hooked up a glass tempering machine that was 600 amp 277/480, apparently the heating elements were 277!

 

[letgomywago]

I hate it when they do, I hooked up a glass tempering machine that was 600 amp 277/480, apparently the heating elements were 277!

Was it to ensure it wasn't used on a 480 corner ground?

 

[ruxton.stanislaw]

You're absolutely right! The 2023 NEC (and previous editions) specifies that electric water heaters typically don't utilize a neutral conductor. Here are some other common devices and appliances that fall into this category:

• Clothes dryers (electric): Similar to water heaters, electric clothes dryers are typically 240V appliances and use two hot conductors without a neutral.
• Ranges (electric): Most electric ranges are also 240V appliances and employ two or more hot conductors without a neutral. However, some electric ranges might have a neutral conductor for specific components like indicator lights or electronics. Be sure to consult the specific appliance's documentation for confirmation.
• Electric furnaces: These also typically function on a 240V circuit without a neutral conductor.

Here are some additional points to remember for your journeyman's exam:

• Identifying 240V Circuits for Devices Without Neutrals: In the electrical panel, these circuits will typically have two ungrounded (hot) conductors and a single grounding conductor. The wires might be black and red, or black and white (identified with black tape to indicate it's a hot conductor in this case)
• Neutral Requirements in the NEC: The 2023 NEC (and previous editions) generally require a neutral conductor for single-phase 120V circuits. However, there are exceptions for specific applications like those mentioned above.

Understanding these exceptions is crucial for safe and code-compliant electrical work. For further reference during your studies, you can consult these specific sections of the NEC:

• Section 210.4: Branch Circuits for Dwellings.
• Section 422.6: Grounding of Service-Supplied AC Equipment.
• Section 550: Electric Ranges, Wall-Mounted Ovens, Counter-Mounted Cooking Units, and Broilers.

By familiarising yourself with these sections and understanding the exceptions for devices like water heaters, you'll be well-prepared for your journeyman's exam.

 

[texie]

Details are important. For example, as a general rule, an appliance or piece of equipment with a data plate that says 120/240 you would need a neutral. On the other hand, if marked 240 volt then it does not need a neutral.

 

[winnie]

Most common ranges and clothes dryers have 120V loads and require a neutral.

 

[texie]

Most common ranges and clothes dryers have 120V loads and require a neutral.

That is my point. Appliances like this will be marked 120/240 not 240.