# How to protect 15-amp circuit from UPS with 20/30-amp draw

I managed to pick up a great deal on a CyberPower OR2200LCDRT2U UPS. Unfortunately this box has a NEMA L5-30P input plug (NOT a L5-20P as specified on the product page). In the location I'm trying to set this up, I only have a 15-amp circuit with a 15-amp breaker. Further, it's basically on the opposite side of the house from the breaker, so I suspect that running a dedicated 30-amp line would be prohibitively expensive.

Now I have found that there are adapters you can buy like this or this but I'm not sure if I am creating a fire hazard by using one. Will the breaker trip immediately if my rack draws more than 15 amps of power? Am I at risk of creating arcing by doing this?

I don't expect to be drawing anywhere near the maximum capacity of this system. Just looking to figure out if I'm out of luck if I don't have a 30-amp circuit already present, or if I can safely adapt down to a 15-amp circuit.

• i only see in the images a 20A plug, which means with simple Eletrcictal Calculation (P=U*I) which means P=120*20=2400Watt and as i understand the UPS has 2200watt wich should fit in case that you dont overload it Aug 18, 2021 at 16:53
• Monitor the load of the UPS, don't plugin things that would result in a a load above 15A, or more safely ~12A. That UPS has load indicators, and I suspect can be monitored if you connect via USB/Serial. If load goes above ~1440W, then alert. Ideally if your 15A circuit has a breaker that isn't cheap shit, it will just break the circuit if you go to high anyway. Aug 18, 2021 at 17:29
• @djdomi, they said the circuit was 15A. They shouldn't go above what the circuit can handle, so ideally they need to stay under ~1440. Aug 18, 2021 at 17:31
• @Zerodrache 15*120=1800 which means basicly that theres a bit still free options. However the 30Amps will only be taken in case you are fully load the UPS Aug 18, 2021 at 17:35
• thank you for your comments...of course I will be monitoring the load, what I'm trying to find out is what happens if I do spike above 1800W: does that trip the circuit breaker or burn the house down? Big difference in consequences, that's all I'm trying to find out. Aug 19, 2021 at 3:24