Resistive load for testing

[sureshot]

I was looking to put together a cheap and cheerful resistive testing load, using 50 watt power resistors. 6 x 2.7 ohm resistors, so just over 300 watts. I would plan to switch in 50 watt increments up to the maximum value.
And I would use forced air cooled cpu heatsink, that can handle 150 watts each. So using two heatsink. Using relays to switch the loads in and out.
Can anyone see anything wrong with this idea, it's not critical for tolerances or presicion, more a quick testing load instead of using halogen  lamps as I've been doing.
Thanks for reading, any feedback appreciated.

[Jwillis]

Really dependent on how many amps and volts you plan on pounding into those resistors.You can max the wattage of one of them with only 4 amps.
You can use the chart below to figure out what your requirements are.

[wasyoungonce]

Why not use lamps?  I often use car lamps, 5W, 12W, 21W, 50W, 75W and 100W bulbs.  They are made to handle the power and have PTC resistance kinda self regulating.  Yes the load is slightly inductive.

FWIW.

[MosherIV]

Need to check the relays can handle the current for the max power through the resistors.

[sureshot]

Thank you for your replys. I've used lamps for a while up to 500 watts, there kind of all over the place strung together in parallel. The resistor idea was going to use an enclosure with meters. I had in mind 6 x 50 watt 2.7R power resistors, switched with 40 Amp automotive relays via a toggle switch on the relay coils.
I'm thinking 2.7R is a bit restrictive for really just around 12 Volt testing. Its converted server power supplies i would be mainly testing. Having thought about it...
6x 3.9R would give a better range from 12 - 14 Volts testing. Around 200 watts at 12 Volts and closer to 300 Watts at the 14 Volt level.
I don't think 2.7R resistor coyld handle the 12 - 14 Volt Range.

[Brumby]

Doing power calculations can give you answers...

At 12 V, a 2.7 Ω resistor will dissipate 53.3 W
At 14 V, a 2.7 Ω resistor will dissipate 72.6 W

At 14 V, a 3.9 Ω resistor will dissipate 50.3 W
At 14 V, a 4.7 Ω resistor will dissipate 41.7 W

[sureshot]

Yes I realised 2.7R is to close, and restricts the voltage I can test at. 3.9R is a bit better, although I will be a little off the 50 watts I'm after from each resistor.
So 3.9R it will be, the cooling is adiqute for the load power.