I have run a 10/2 electrical line from my panel to my garage to run a dust collector motor (which uses 10 amps at 220v) simulatneously with other tools such as a table saw (which uses 12.8 amps at 230v). Can this line handle this or am I close to maxing out the 10/2 lines capabilities? Would I be safer running a dedicated line just for the dust collector motor and using a different line for my woodworking machines?

What amperage breaker do you have on the 10/2? Voltage in US is now 120 or 240VAC

I installed it with a 20 amp breaker. I'm concerned about either the line over-heating or not having enough flow to run the machines simultaneously. Would this problem be fixed by simply installing a higher amp breaker such as a 30?

10/2 is rated for 30 AMP. The load you give us is already over 20 Amps-I assume you used a double pole. How far is it from the panel to the shop. 12.8 +10 =22.8 X 125% (motors)=28.5. Actual Amp draw is a bit less based on 240 vs 220 or 230 VAC. Unless you are a long way from the panel, it should be OK.

What on the planet are you? This is an international site. You won't be running a two wire circuit at 220v (nominal) at home in the USA or Canada. That would require three wires plus a ground.

Straight 240 only requires 2 wires plus a ground, no neutrtal. White is recoded to a black, very common practice for Hot water heaters..

Will I be OK with the current 20 amp breaker or would I need to replace it with a 30 amp breaker? My garage is attached to the house however I ran the line through my basement, up into the attic over the garage ceiling (attached to the trusses) and down on the far outside wall. I used roughly 80' of a 100' reel with a junction in the attic (at the junction I dropped a line inside of one wall for some outlets in the garage and then ran another line to the far side wall and dropped that line for outlets on the oposing garage wall). What I want to know is if the line will overheat and cause potential fire hazards if running these two machines on this line, and if running these machines will trip the breaker. I know machines use their max amperage at start-up and then drop a bit so I would never start both machines at the same time. Also I wouldn't be running two machines for a very long at any given task. Where are you getting the 125% from for your equation? Also how would I know if I used a two pole line? I really appreciate your input - thank you.

You will trip the 20 Amp breaker since your combined load is almost 23 Amps not counting any startup draw. NEC requirement for more than 1 motor or a motor and other loads... "current multiplied by 1.25 shall be used...." In a straight 240 application, you will have a 2 wire connection, both wires at 120VAC. On your 10/2, where is the white wire in the panel box connected? You do know the difference between a 120 and 240 receptacle?

"at the junction I dropped a line inside of one wall for some outlets in the garage and then ran another line to the far side wall and dropped that line for outlets on the oposing garage wall).

Wait a minute! If you are using 10/2 on a 240 volt 20 amp circuit you sure better worry about a fire!!

Apart from using equipment that would be over the 50% limit for "Equipment that is fixed in place", where are you getting the Neutral for your receptacle outlets?

While it is true that you can use a 10/2 cable to feed a straight 240 volt piece of equipment (both conductors will be ungrounded or hot) there would be no way to supply a Neutral conductor for the receptacles (120 Volt). For this branch circuit to supply 120 Volt receptacles, you would need a minimum of a 10/3 cable with a ground conductor. As stated earlier, the circuit breaker needs to be replaced with a 30 amp breaker.

However, you would be wiser to remove the 10/2 cable and install at least a #4/3 (two ungrounded conductors Black/Red - one grounded White conductors and an insulated ground conductor) using a 70 amp breaker to feed a panelboard in the garage.

That way you could have a 30 amp circuit for the dust catcher and saw as well as several 120 volt outlet receptacles.