Unusual voltage drop?

[Bryman]

So... I was testing the voltage on my power supply, with only about 1 amp of load running on the circuit, my power supply was reporting 124 volts

 

Now, I tried 2 different room heaters into the same extension cord my computer is plugged into, one dropped the voltage from 124>118 on low and 124>115 on high, the other dropped the voltage from 124>116 on low and 124>113 on high

 

When plugged into the other plug on the outlet, the more power-hungry room heater was only dropping the voltage from 124>115

 

Both room heaters are rated 1,500 watts, but the power draw is different

 

Is this an unusual voltage drop? The power supply I have is an 860i

 

Short version: voltage is dropping about 10 on a 120 volt circuit with 1 amp of load versus about 14 amps of load on a 15 amp rated circuit

 

Basically why I'm posting this is I'm wondering how likely it is that the power supply could be reporting inaccurate voltages, because I think the voltage drop is too much

[Vegan]

with that much load you may see some sagging, almost all power supplies will be OK down to around 90V before they cannot get enough current to operate

[Bryman]

I read that anymore than a 8% voltage drop is considered a fire hazard, if I read it correctly

 

So my power supply is reporting my voltage dropping about 10%

 

Edit: Hmm.. I must of misread it, I think it's only a hazard if the voltage is too low for the equipment to operate properly

 

Now, a few days ago, there was only about 500 watts running through the circuit, I went to plug in this really big subwoofer into the circuit, and right as the edge of the prong hit the outlet it shut the receiver off

 

Subwoofer spiked the voltage too low for the receiver?

 

When the prong hit the outlet, I saw a big spark

 

I think the power supply is reporting the correct voltage, so I'll have it looked into, because a 10% drop is a little more than normal

 

with that much load you may see some sagging, almost all power supplies will be OK down to around 90V before they cannot get enough current to operate

 

Thanks, that's good to know, but I don't think all my electronics would be able to run that low :/ Maybe not even at 110, so I'll do some more testing with different circuits