Antminer S9 new firmware with adj. Low Power Mode safe for 120v outlet AP3W++ PS

[AESyn]

I understand normally, 220v outlet is recommended on the AP3W++ power supply for the 1600 watts on a normal running S9 with all 3 hashboards.

However the new firmware allows users to lower the hash rate manually (thereby lowering wattage) as well as default selections "Low Power Mode" and even "Enhanced Low Power Mode" which offers almost 40% reduction in watts. I've read somewhere the low power mode brings the S9 down to 1258 watts. I've also r ed ad enhanced low power mode brings it down even further to 1000 watts or even lower.

My outlet is 120v with a 20 amp circuit breaker and I am using 14 gauge power cable. Can I use the Low Power mode, manually lower the hash rate by 1 or 1.5 Th/s or even  run in Enhanced Low Power Mode and be safe to run to the 120v outlet with 1 AP3W++, since my S9 now requires 1258 watts and even less in the more aggressive power settings?

If I dont care about efficiency, just safety, what is the best combination of manually lowering hash rate, using low power mode or enhanced low power mode to maximum hash rate possible  but be safe on a 120v outlet?

[tim-bc]

As you probably know, there are more losses (wasted as heat, needs thicker cables etc) when you transmit power at lower voltages, and also the APW3++ itself is less efficient at 120. See here - http://timbrown.me/efficiency.png

Enhanced LPM is always the best mode as far as least power draw and most hash per watt. It is almost 50% power savings compared to stock Nov 2017 fw (no asicboost). This would be safest if you must run on 120v.