Hi Folks, On 22 October 2011 12:30, Terry Coles <d-...@hadrian-way.co.uk> wrote:
> On Saturday 22 Oct 2011 11:55:59 Tim wrote: > > After posting this last night I thought about a 1kw heater in > > conjunction with a meter that will measure the va for me. I am going to > > get one of these > > > > http://www.maplin.co.uk/plug-in-mains-power-and-energy-monitor-38343 > > > > APC tech support say the load should be +\-5% so I think should be able > > to give it a go with those bits. > > There are some problems with this: > 1. A 1 kW electric fire only uses a nominal kW of energy, it's more when > you > first switch on, then it settles to approx 1 kW once it has warmed up. > > 2. +%5 of 900 W is only 945 W, so if your heater consumes energy on the > high > side, you're going to be out of APC's spec. However, I'm not convinced > that > the 5 % figure is that critical. After all, you only want a representative > load I would have thought. If APC's spec is critical though, then you > might > have to think again. > > You may have to resort to the light bulbs after all unless anyone has any > other bright ideas. (No pun intended.) I quite agree with Terry here, the 1 KW fire is the simplest, easily available load that comes close to what the APC tech is asking for, he's also quite right about the initial power, but then APC were looking for a steady state load, so you'd get that after about 10 minutes, not too bad I don't think. Light bulbs would definitely be a more accurate way getting the requested load, and if you could get some 150 Watt Bulbs, (they do exist), that would only need 6 of them. In answer to Ralph's question, yes you can buy Electronic Loads that be set to any specific load value, I've never seen the price of one, but I'd guess they probably start in the high hundreds and climb rapidly ! One question, did the APC tech ask you for a constant, or minimum load of 30% ? I've looked at the Maplin you sent and I agree that as an initial test, this and a 1 KW fire would at least get you started and may even keep APC happy. Good luck. -- Cheers Peter -- Next meeting: Bournemouth, Tuesday 2011-11-01 20:00 Meets, Mailing list, IRC, LinkedIn, ... http://dorset.lug.org.uk/ How to Report Bugs Effectively: http://goo.gl/4Xue
