Exeltech XP 1100 W Inverter Review

Exeltech XP 1100 W Inverter Review
12 VDC, 120 VAC, 20 W idle current

INSTALLATION

I purchased 4/0 guage copper wire for the battery leads and a 250 A fuse. The way the battery wires connect to the rear of the inverter is a nightmare. The bolts for connecting the battery wires are too close together making it easy to accidentally short circuit the battery array. I carefully placed electrical tape on the wire lugs to minimize the chance of an accidental short circuit. Being attached to a printed circuit board, the bolts do not appear to provide much strain relief. One of the bolts, the negative terminal, does not align with the hole in the side where the 3/4 inch EMT strain relief is located requiring the wire to make a very sharp bend to get through it. Naturally, the lugs and the 4/0 gauge wire are too large to fit through a 3/4 inch EMT fitting. I suspect a lug for 3/0 gauge wire would also not fit.

Instead of sending the battery wires out sideways from the inverter, it is easier to drop the wires strait down through the table since it is mounted above the battery array. I had to remove and not replace the metal cage that goes over the wiring on the rear exposing the wiring and printed circuit board to potential short circuits. To cover the rear air vent to keep insects out and to prevent short circuits on the PCB, I glued nylon screen with 1/16 inch mesh over the circuit board. When finished with the wiring, I wrapped more nylon screen around the rear to replace the metal cage. Concerned the bolts mounted to a PCB are too weak to bear the weight of the negative battery cable, I fabricated strain relief as the wire pass through the table. The positive battery cable is only 1 foot long before it attaches to the fuse located beneath the table hopefully making it light enough for the PCB to bear its weight.

Following advise given elsewhere on this site, I put nylon screen under the fan guard on the front of the inverter to prevent insects from entering. A rocker switch would be a better power switch than the toggle switch flanked by guard rails that is present on mine. The inverter would fit better on a shelf or table if its shape was more square like the Trace inverter instead of long and narrow. It would be nice if AC sockets were located on the side of the inverter. The way everything attaches makes it occupy a lot of length.

OPERATION

This little inverter is quite impressive in what it can power. It started everything I tried except a 3/4 horsepower motor on an air compressor. It dutifully tried to start it for 3 seconds before tripping the overload and shutting the inverter off. Exeltech's owner's manual is vague about the proper fuse rating (219.8 A on page 12) so I was relieved that my 250 A fuse did not blow during this test. I calculated the value as follows:

maximum surge power for 3 seconds is 2200 W
worst case input voltage is 10.4 V
peak efficiency is 87%

2200 W / 10.4 V / .87 = 243 A

The closest fuse with a higher rating is 250 A. Because my battery array was around 12 V during this test, which is far from the lowest battery voltage, I still wonder whether I should have picked a 300 A fuse because the efficiency is likely somewhat lower than peak during surge.

Some difficult things this inverter is able to start and operate one at a time with air temperature between 10 C and 15 C:

drill press, unknown power rating but it is difficult to start
grinder, 1/3 hp split phase motor, 249 W, difficult to start
electric chainsaw, 1440 W
circular saw, 1265 W
circular saw, 1200 W
refrigerator/freezer, ~1200 W to start compressor motor
induction cooktop, Sunpentown Mr. Induction SR-964T, 500 W to 1300 W
microwave oven, 1050 W (700 W of microwaves)
vacuum cleaner, 700 W

As for a convection microwave oven it does fine running the top heating element that consumes 1000 W used for grilling. It runs the magnetron that consumes 1450 W (900 W of microwaves) and heats water, but the feature of this inverter that clips the peaks of the sine wave to limit power obviously underpowers the oven.

I have a review elsewhere on this site describing how my induction cooktop operates with my Trace 2012 modified sine wave (rectangular wave) inverter. Unlike the Trace this Exeltech inverter regulates the AC voltage which makes it easy to start and keep the cooktop running. My Tramontina tri-ply clad pot operates quietly with this inverter suggesting the rattling and squealing was caused by the rectangular wave. The 100 W and 300 W modes still provide continuous power instead of cycling on and off as described in the owners manual suggesting this malfunction has nothing to do with the power. The problem about the cooktop shutting off when using my large iron skillet was solved by removing the white paste around the temperature transducer so I can not be certain this problem was related to MSW or sine wave power (I suspect not). The cooktop continues to have problems starting and keeping the coil powered when certain other electric things are operating elsewhere in my house, but it is more tolerant when powered by the Exeltech than the Trace inverter. I suspect this problem is related to the amplitude of the voltage because it is also more tolerant when the Trace inverter runs at night with a lower battery voltage. In summary the cooktop works better with the Exeltech, frustratingly with the Trace and not at all with the trashy Chinese Whistler Pro 2000 W MSW inverter that broke after 1.5 years with minimal use.

Some observations:

Lights running on AC blink when the fan turns on and more so when it turns off, that is, the fan turning on or off puts a voltage surge on the AC line.

The case is warm when in operation.

The fan is noisy which does not matter to me because it is located in a shed, but if someone wants to operate it in a house or vehicle, the noise could be an issue.

The fan does not appear to have various speed settings. It is either on or off depending on how much cooling the inverter needs.

The owner's manual is minimalistic.

The AC power sockets are 1/4 inch apart which is too close to use both simultaneously when the power cords have large connectors.

The inverter operates with the neutral to ground bonding strip removed.

The inverter operates whether or not the case is grounded.

The diameter of the bolts for the battery wires is 5/16 inch which is not shown on the drawing on page 16 of the owner's manual dated 2010 and incorrectly stated as '3/8"' on page 5.

According to my measurements, the lower the air temperature, the greater the load it can power even in excess of 1,100 W. It is rated at 1,100 W at 30 C with 20% derate per 10 C change. That suggests 880 W at 40 C, 1,320 W at 20 C and 1,540 W at 10 C. It ran a resistive load of 1,206 W without clipping the waveform with 15 C air temperature.

When idle and fan off, my measurements show the inverter consumes 14 W to 16 W although Exeltech claims 20 W. My measurements show the fan consumes between 10 W and 21 W with all but 1 measurement between 17 W and 21 W.

On my oscilloscope the waveform is a clean sine wave over its nominal operating range with resistive and some inductive loads. The AC voltage does not change as the voltage of my battery array drops from 14.2 V to 11.8 V. When running the induction cooktop, there is a little distortion. I have attached 4 photos of the waveform with various loads:

Attachment not found.
EXELTEC0.JPG
The AC waveform of the Exeltech XP-1100 inverter with a load of refrigerator / freezer, 20 W CFL, 26 W CFL and oscilloscope. This is a typical clean sine wave output by the inverter.
Ambient temperature: 53 F.


Attachment not found.
EXELTEC1.JPG
The AC waveform of the Exeltech XP-1100 inverter with a load of Sunpentown Mr. Induction Cooktop in 300 W mode (~700 W actual power consumption), 20 W CFL, 26 W CFL and oscilloscope. The induction cooktop distorts the sine wave a little.
Battery voltage: 12.9 V.
Ambient temperature: 54 F.


Attachment not found.
EXELTEC2.JPG
The AC waveform of the Exeltech XP-1100 inverter with a load of Sunpentown Mr. Induction Cooktop in 1300 W mode (~1200 W actual load), 20 W CFL, 26 W CFL and oscilloscope. The induction cooktop distorts the sine wave a little, and the waveform is not being clipped probably because the low temperature increases its operating range.
Battery voltage: 11.98 V.
Ambient temperature: 56 F.


Attachment not found.
EXELTEC3.JPG
The AC waveform of the Exeltech XP-1100 inverter with a load of convection microwave oven running the magnetron at full power of 1450 W, 20 W CFL, 26 W CFL and oscilloscope. The Exeltech inverter is clipping the sine wave to limit the power to its maximum continuous rating. When powered by this clipped sine wave, the microwave oven heats water.
Battery voltage: 11.84 V.
Ambient temperature: 58 F.


Attachment not found.
EXELTEC4.GIF
The efficiency of the inverter is calculated from measurements of the voltage drop across the negative lead and 2 wire lugs with a resistance of about 243 microohms including temperature correction for the copper wire. The load is incandescent lamps. The power dissipated in the battery leads, fuse and lugs is included as inverter power and introduces a maximum error of about 1%. I can not accurately determine this power becuase the resistance of the fuse appears to decrease as the current increases. The peak efficiency in my data is 90.3% with a load of 362 W which agrees with Exeltech's claim that peak efficiency occurs at 1/3 rated power. Exeltech claims the peak efficiency is 87% and typical efficiency is 85% at full power in their specification sheet dated March 2008. Exeltech's numbers are probably stated at 30 C while my data was collected at an ambient temperature of about 8 C which likely explains the difference. With higher air temperature the inverter's fan turns on at lower power loads and negatively impacts the efficiency. The fan first turned on when the load was about 750 W, but when I did an earlier test at 12 C, it first turned on with a load of 650 W. When the temperature is 30 C, the fan probably turns on with a load around 300 W. The vertical points at 250 W, 750 W, 850 W and 900 W represent the fan being on or off. The points at 250 W include a reading with the fan on because I took the reading after turning off most of the lights but before the fan turned off, but generally I read the data starting at 25 W and increased power toward the maximum. Except for the mentioned point, the fan was off in all data below 700 W and, on in all data above 950 W. I measured 84% and 83% efficiency near full power which reasonably agrees with Exeltech's claim of 85%. Basically the efficiency is between 80% and 90% when the load is between 100 W and 1100 W but is very bad when the load is less than 100 W due to the high idle power consumption.

Comments

  • BrluxBrlux Solar Expert Posts: 73 ✭✭✭
    Wow, great review. I have always loved Exeltech Inverters. I am always amazed when they start things I think are just out side of there capability. I ran a 48V XP1100 nearly non stop for about 8 years and it was fantastic. I also had a SW4048 but primarily ran the house of the XP1100, the power quality out of the Exeltech was far better. The ceiling fans would emit an audible buzz on the stair steeped sine wave of the SW4048, it was really annoying to listen to when trying to go to sleep. I now only have 12V setup as I could not justify the expense to replace all my batteries on my 48V system for a hobby system. I am running an XP600 on this 12V system which has 4 new T-105s.

    One thing I find interesting about the Exeltech XP series design is it is nearly an analog design. It does have a clock that drives a counter, probably for frequency control. But there is no proprietary microprocessor and all the components inside (minus the magnetics) are off the shelf parts that can be bought from nearly any component supplier. The XP2000 does have a microprocessor.
  • PhotowhitPhotowhit Solar Expert Posts: 5,222 ✭✭✭✭

    I purchased 4/0 guage copper wire for the battery leads and a 250 A fuse. The way the battery wires connect to the rear of the inverter is a nightmare.

    Since this is a review, lets let people know you can go up to 20 feet away from your battery bank with 3/0 and '0' up to 5 feet. I usually recommend moving your inverter closer to your batteries rather than running heavier cable. Anything larger than 1100 watts and I'd also recommend running a higher DC voltage. I don't think 2 '0' welding wires would be a problem. I run a 24v system and 2 - 2 gauge (11? strand) aren't a problem.

    Most experienced people will likely see the low voltage and high amperage as the 'nightmare'.

    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, 660 ah 24v ForkLift battery. Off grid for @16 of last 17 years. Assorted other systems, and to many panels in the closet to not do more...lol
  • H2SO4_guyH2SO4_guy Solar Expert Posts: 213 ✭✭✭
    I like them and have several. Smoked a 48 volt version when a Trace C-40 let go and the string of 4 Evergreen panels coming in at voc of about 88 volts apparantly overvoltaged the Exeltech and the magic smoke was released. I was standing 3 feet away from it when it happened. Watching something actually fail doesn't happen too often.

    I leave the end off and use external stress relief on the 2/0 welding wire on the 12 volt versions. I am careful to tighten the lugs as they are connected directly to the board. I always wanted the 108 volt version so I could use junk batteries of lower capacity and use less strings, but never invested in the system. The rack mount Exeltech stuff is pretty good, but much of it is getting fairly old and with a MTBF of 20 years, quite a bit is that old or older.

    Thanks for such a good review. Overall they are quite good and even more so when purchased second hand at a good price. I have picked up 125 watt versions @ 24 volts for as low as $35.00 each. How do you beat that?

    12K asst panels charging through Midnite Classic 150's, powering Exeltechs and Outback VFX-3648 inverter at 12 and 48 volts.  2080 AH @ 48 VDC of Panasonic Stationary batteries (2 strings of 1040 AH each) purchased for slightly over scrap, installed August 2013.  Outback PSX-240X for 220 volt duties.  No genny usage since 2014. 
  • PhotowhitPhotowhit Solar Expert Posts: 5,222 ✭✭✭✭
    H2SO4 Did you send the inverter back to Exeltech? I haven't checked but as recently as a year ago they appear to offer a rebuild for $100, perhaps the most outstanding feature. If they no longer offer this I'd like to know. One of the reasons I suggest people look into buying them used.

    ...We also still support and repair units from 20 years ago, and do so for a flat fee. Case in point: If you accidentally reverse connections on an XP1100 inverter you bought in 1994, or an MX module from 1993 .. or even an old SI1000 from 1991, and blow it up .. if it's repairable, we'll fix it for $100 and (if possible) upgrade it at the same time. Turn-around time generally averages less than a week.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, 660 ah 24v ForkLift battery. Off grid for @16 of last 17 years. Assorted other systems, and to many panels in the closet to not do more...lol
  • H2SO4_guyH2SO4_guy Solar Expert Posts: 213 ✭✭✭
    Thanks for the tip Photowhit! Haven't looked into it, just hasn't been too much of a priority since I got the VFX-3648. That thing is a beast! How many heat their place with batteries? hehe. I am with you in that I don't want to use gas if possible, but do for backup when there is not enough sun. That last stretch of 17 days with only 3 days of partial sun was tough, but still didn't run a genny! I did heat with propane during that time however. Finally got the rest of the panels up and now have gobs of power. Most of my time is now consumed trying to raise money to get the property across the road from me that is 3 acres with a pond. That would keep neighbors that much farther away from me! Not that I am a hermit or anything, just would prefer neighbors a bit further away.

    We should work out a visit when you are up this way sometime. I lost your number with the last phone that had a tragic meeting with a brush hog......oops. You would get a kick how I switch panels to different charge controllers. Eventually this is going to be an off-grid aquaponics setup, but it is sure taking a LONG time. My buddy just came back from building a prototype of a frameless geodesic 10' dome as proof of concept. We may start making 20' domes out of double wall polycarbonate for greenhouse purposes.

    Always appreciate your willingness to help others and you sure have helped me along the way.

    Skip
    12K asst panels charging through Midnite Classic 150's, powering Exeltechs and Outback VFX-3648 inverter at 12 and 48 volts.  2080 AH @ 48 VDC of Panasonic Stationary batteries (2 strings of 1040 AH each) purchased for slightly over scrap, installed August 2013.  Outback PSX-240X for 220 volt duties.  No genny usage since 2014. 
  • PhotowhitPhotowhit Solar Expert Posts: 5,222 ✭✭✭✭
    I'm just about out of wood, but it's warming up, had a fire last night for the first time in 10 days or so, I was out of town last time it dropped to just below freezing. Taking down a big 'standing dead' red oak in the next week, should be half the wood for next year...

    Maybe, some day, I'll get a 'real' inverter. But I have a back up and a repairable for my Prosine as well as the 1100 watt Exeltech, which I just use for outside things, but up and running should I have a Prosine failure. Would be nice to run the microwave this morning, while I'm washing clothes and cooking water(water heater) with the fridge kicking on and off...

    I'm PM you contact info, I'm always good about loosing stuff, so rarely try anymore, just save all my Email...lol.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, 660 ah 24v ForkLift battery. Off grid for @16 of last 17 years. Assorted other systems, and to many panels in the closet to not do more...lol
  • SolInvictusSolInvictus Solar Expert Posts: 138
    Photowhit wrote: »
    Since this is a review, lets let people know you can go up to 20 feet away from your battery bank with 3/0 and '0' up to 5 feet
    Sure, I used larger battery leads than Exeltech recommends for a distance of a few feet to minimize the voltage drop and to allow me to reuse the leads if I ever replace the Exeltech 1100 with a more powerful inverter.

    With ambient temperatures between 20 C and 25 C in April, my Exeltech has continued to power all of the high power equipment that I listed. I cut lumber with one of the circular saws while the refrigerator was running adding an extra 220 W without it clipping the sine wave.
  • TonygreenTonygreen Registered Users Posts: 15
    I agree. Those battery post are just awfully placed.
    Like you, what I did was to drill 2 holes in the wood panel under the inverter, so that both cables (+ and -) go through them straight to the inverter, making it impossible for them to touch each other.
    Here are some pics, though you may not be able to clearly see the installation, since the inverter is inside a mosquito screen box custom made to protect it.

    Sorry! No photos! When I tried to upload them, there is a message/warning that says "File exceeds PHP's file-size limit of 2.00 MB."
  • westbranchwestbranch Solar Expert Posts: 5,183 ✭✭✭✭
    don't believe that limit .... it is way smaller than that by my experience...that size may be as small as 2 kb, I kept reducing and never did find how small it has to be, my avatar was a right pain...
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • PhotowhitPhotowhit Solar Expert Posts: 5,222 ✭✭✭✭
    Sure, I used larger battery leads than Exeltech recommends for a distance of a few feet to minimize the voltage drop and to allow me to reuse the leads if I ever replace the Exeltech 1100 with a more powerful inverter.

    If you go with a larger inverter, please consider a higher voltage battery bank, 1100 watts would be as high as I would take a 12 volt system and one of the reasons you might have problems before going with over sized cables.

    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, 660 ah 24v ForkLift battery. Off grid for @16 of last 17 years. Assorted other systems, and to many panels in the closet to not do more...lol
  • SolInvictusSolInvictus Solar Expert Posts: 138
    Photowhit wrote: »

    If you go with a larger inverter, please consider a higher voltage battery bank....
    I wish my PV system was 24 VDC, but it was installed 24 years ago making me stuck with a 12 V system. In my opinion 2,000 W to 2,400 W is maximum for a 12 VDC PV system. The Exeltech 1100 W is merely a backup inverter for my 24 year old Trace 2012 inverter which is considerably more powerful than the Exeltech but outputs a modified sine wave and does not regulate the AC voltage. When the Trace inverter finally breaks down, I will be considering the Exeltech XP 2000 or one of the Outback inverters at 12 VDC, if nothing else better is available. I wish Trace Engineering had never sold out because they made the best off-grid inverters.
  • mike95490mike95490 Solar Expert Posts: 8,820 ✭✭✭✭✭
    I wish my PV system was 24 VDC, but it was installed 24 years ago making me stuck with a 12 V system...
    It should be fairly simple to rewire half your array and put it in series. It will make battery management much easier than parallel strings.

    Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||
    || Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
    || VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

    solar: http://tinyurl.com/LMR-Solar
    gen: http://tinyurl.com/LMR-Lister ,

  • PhotowhitPhotowhit Solar Expert Posts: 5,222 ✭✭✭✭
    What Mike said!

    We can't see what your system looks like. When I switched from 12 to 24 volt, I had planned ahead. I had purchased 8 panels at 12 volt nominal with the idea I could use them in a 24 or 48 volt configuration. When it was time to change out my dying batteries, but not time to switch to 24 volts, I purchased 4 - 6 volt batteries and ran them in a 2x2 configuration (2 strings of 2 batteries) a year later I setup the 24 volt system, I just put them in series...

    ...So start thinking now, when things need replacing try to make the array and battery bank usable in either configuration. Then when it's time to replace the inverter you can easily make the move to 24 volts.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Prosine 1800 and Exeltech 1100, 660 ah 24v ForkLift battery. Off grid for @16 of last 17 years. Assorted other systems, and to many panels in the closet to not do more...lol
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