| Author |
Message |
ktrout (207.190.253.82)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, October 30, 2001 - 7:41 am: | |
Looking at the big expense of an inverter, I want to try to get it right the first time. Does anyone have experience with the Trace DR series ? I'm looking at the DR2424 or 3624 in particular. I plan on having a pretty good load with a full-sized fridge and two rooftop units for HVAC. I have a 5500W genset and plan on an appropriate sized house battery bank to round out the system. |
Tom Caffrey (Pvcces) (12.146.33.155)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, October 31, 2001 - 12:42 am: | |
Hi, ktrout. The DR series is intended to cover the RV market, but it is a modified sine wave unit, I believe.
On the manufacturer's ratings, it looks as though they are more efficient, but Fast Fred has pointed out that large AC motors and microwaves perform less efficiently on them, so that the savings may not be worth it.
Are you planning on running one or both AC units on the inverter? I have no doubt that you can get the first one started and I expect that you can get the second one going on the large inverter.
The power consumption is really going to get your attention. I wouldn't be surprised if you ran down the batteries just cooling the coach off.
For a 24 volt inverter, multiply the AC amps by 5 1/2 to get the DC amps that you will need from your batteries. If you need 30 amps, then your batteries will need to put out 165 amps. Even 4 Trojan L16 batteies will not last long at that rate.
They have around 450 amp hour capacity, and as a rule of thumb, you will not want to discharge them below 50% or recharge them above 85% if you're trying to run air conditioning without a generator running.
35% of 450 is barely over 150 amp hours, so you would need to start the generator after only one hour, and if you recharged at C/10, which is about tops, you would need more than three hours to recover.
That is true only if you have 45 amps to recharge with. If you have a 30 amp shore power cord, and the are running both air conditioners off of it, the power sharing circuit of the inverter will cut the charge current way down to avoid overloading the 30 amp circuit.
The long and the short of it is, see if you can figure out how to balance competing needs under the conditions that you will operating in.
For example, the greatest electrical needs are likely to occur in the hottest weather. If that is true in your case, you will have to look at whether your inverter will be derated at that temperature.
Your batteries will need to be derated if the temperature climbs much above 80 degrees and they will tolerate less recharge at higher temperatures.
I've personally experienced thermal runaway in deep cycle batteries when in Pheonix earlier this year. Once it happens, all you want to do is stay away from them, because even though they are disconnected, they just keep getting hotter until they run out of power.
Our batteries would not take any charge after that.
Hope this helps!
Tom Caffrey PD4106-2576 |
jmaxwell (66.42.93.5)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, November 01, 2001 - 12:23 am: | |
4 yrs. ago I bought a DR series, 12v, 2500w. Tripped out on continuous use of 1 roof air--after about 30 mins. Talked to an engineer at Trace and was informed by him that they do not recommend the DR series for heavy or continuous induction loads, even though the manual says nothing of this limitation and in fact, implies that it is designed to run such things as well pumps, etc. He explained that the wave pattern only has 13 steps of inversion compared to the U series, which was originally designed for marine use, which has 21 steps. Until the intro of the SW series, the U series is what they recommended for RV use. I traded my DR for a U1225 and run my rooftop air for hours at a time while on the road, running from the inverter. Of the 2 or 3 DRs that I know of being used, they are not used for continuous induction loads, such as a refrig or a/c. |
Steve Fessenden (63.27.89.14)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, November 01, 2001 - 8:29 pm: | |
Cruiseair told me that they have lots of Trace DR series running their A/Cs with no problelm. Marine stuff with exact specs. Maybe the roof air needed more than its rated power.
Hint: Check pricing at www.altenergystore.com wherever you actually buy. It gives a good idea of the best deals available on new inverters. Good way to avoid paying 85% of new cost for a used one on Ebay. |
|