URGEANT: 240V Hook Up Question:Hooking up 10-3 cord

Is it ok to splice the ends a 10-3 cord and add another 10-3 cord to make the run longer. I currently running only 50 ft but wanna move my grow into the back room which is further away so I need another 50 ft or wiring. So I went out and bought another 50ft 10-3 wire and bought some split-bolt connectors to hook them together.

Is this safe?

It's safe only if you are 100% positive there will be no stress or pulling on the cable.

Put those connectors in a junction box with the appropriate knockout connectors/antishorts that's attached to a stud and you should be ok.

This is not a recommended practice because the weight of #10AWG makes it more likely to pull out of a junction box/break wirenuts, so that's why it's not code in my understanding.

EDIT:

P.S. Electrical work shouldn't be urgent. If you need to stop and think about it you should stop and think about it.

Cheap fix is buy a blue nail on plastic box run wires in strip connect color to color with blue b-4 wirenuts and twist the ground witted tightly together it doesn't need a wire nut buy a 2 gang blank cover lay out on the ground or wherever you want as long as it's not a trip hazard liscensed electrician here have any questions shoot doubt anyones grow room is wired to code lmao

Basically can i connect 2x50ft 10-3 cords together and have a safe grow?

yes just use a junction box like explained above

Not really. 40' is generally the longest distance for 10ga @ 30amps. If you want to go 100' you should upgrade to 6ga. If you're hardheaded and don't like code then there's two ways to test for safety. One is using a meter at the panel to measure voltage and then at the load for voltage. If it's greater than a 3% drop the wire is undersized. You can also put your hand on the breaker or wire when running your load. If it's too warm it's too small. Generally warm is too warm. Last thing you want is an electrical fire. Overtime the warmth will cause a breakdown in the wire's insulation and an arc to occur.