# What is the real and apparent power of these steel cutters?

The US market model of this steel cutter is 120 VAC, 13.0 Amp.

The NZ market model is 230 VAC, 1,100 W.

I am trying to wrap my head around whether 1,100 W is the real power and so whether the apparent power is 120×13 = 1,560 VA. That comes to the power factor 1100/1560 = 0.705.

Does that sound right for such a tool?

Or, maybe the 2 variants are a bit different in their power?

• Why do you need to know it? Apr 28, 2022 at 12:25
• @user253751 Just curious 1) whether the one I bought is the same as the other one, or more/less powerful; 2) Why the US version's power is noted by Amps, not Watts. Apr 28, 2022 at 12:50
• In general, if sold to consumers who don’t pay for apparent power it’s real power and real current. If sold to industry and grid owners, it’s apparent current. A W is always a W though. Apr 28, 2022 at 13:32

The 1100 watt rating is very likely the real power for sustained operation. The specs seem to support that.

The 13 amp rating is likely the maximum momentary current. In operation, you would find that the saw is slowing down and losing cutting effectiveness when the current reaches that level. If you persist, the saw will overheat and likely trip the breaker in the service box. In the US, products are required to be marked with current ratings based on worst-case load on the distribution system.

The saw has a universal motor, so the power factor is likely higher than 0.7.

Real power is specified in watts. Apparent power is specified in volt-amps (or VA or kVA). So, if the input specification is 120 volts at (presumably) a maximum of 13 amps (both volts and amps in RMS), then all that can be said is that the apparent maximum power of the device is 1.56 kVA.

That comes to the power factor 1100/1560 = 0.705. Does that sound right for such a tool?

It certainly sounds a reasonable figure.

I don't see any basis for accurate comparison, there is too little information given. The manuals give even less information than the blurbs.

Given the size of the brushed universal motor appears identical the power output is probably very close to being the same. From the linked reference below, the power factor of universal motors is given as the range 0.7 to 0.9, with the lower figure applying to the maximum power input. Image below from here

The effect of armature inductance will be higher at 60Hz than 50Hz so there may be some slight difference as a result of that, even with the motor designs fully optimized for each situation.

There are instances where the 240V appliance has higher power capability because of outlet limitations for the North American market (eg. kettles where ~3kW is possible in Europe) but that does not seem to be clearly indicated in this particular case.