Run 20 amps of lights on 30 amp dryer outlet with Helios 7 8light controller?

Hello.
Beginner grower here.
I am curious about the electrical setup for a new room that has been revamped.

Current setup:
10/2 Romex cable running from the 30amp dryer outlet in my hallway to Helios 7.(8 light controller)
(6) 315w CMH (<2amps each)
(2) 1000w DE HPS (<4 amps each)

The question:
Is it possible to safety hook up and run the wire that I have to the Helios 7 box with the equipment described above?

As I understand the 10/2 cable I have has 1 ground 1 nuetral and 1 hot line.
The Helios 7 box I purchased has inputs for 2 hot lines and 1 ground and 1 nuetral?
Is it possible to somehow hookup to the box without buying new wire and run the 20amp load which is way less than usual for this box?

A 220v setup does not require the separate ground, the power goes through the two hot wires and the neutral becomes the chassis ground.
The controller sounds as if it splits the two hot wires into a pair of 110v circuits which use hot to neutral for power and a ground wire to the equipment frame for safety.
Although the neutral and ground wires are connected downstream of the house wires it is not recommended to connect them at the unit. RF interference is the simplest explanation for that, although there are other issues as well.

A separate grounding wire zip tied to the supply cable would look untidy but be entirely functional and safe.

I'm no electrician but As long as it s 240 volts and hooked up correctly you ll have 30 amps. Dont buy a bigger breaker unless you buy larger wire also.