No, you can’t combine the two circuits because of NEC 300.3(B).
Why don’t you need a neutral for 240V?
Note: 240V in the US is split-phase and doesn’t use the 120V neutral. 240V in the UK is single phase with one live wire, one neutral (and always one earth wire). short answer: it’s because the two, 180 degrees out of phase, feed wires essentially take turns being the return wire every time the phase switches.
Can 120V and 240V in same conduit?
There should be no problem doing what you want, as long as all the conductors and overcurrent devices are sized properly. As per National Electrical Code, you’ll size the equipment grounding conductor (EGC) based on the largest overcurrent device used.
Does a 240V circuit need a ground?
240v circuits use two hots and a ground. There is no neutral. If the appliance (like a dryer) uses 120v for a light and blower motor, there are two hots, a neutral (for the 120v needs) and a ground.
Can I use one ground for two circuits?
So if your area has adopted NEC 2014, you can connect a grounding conductor to the grounding conductor from another branch circuit, as long as both circuits originate from the same panel.
Can two 120v circuits share a ground?
The code requires each branch circuit to have an equipment ground (either a wire, or conduit, or cable tray as in 250.120A), they can be shared when they are in the same raceway.
