Lights flicker on XW6048 when freezer starts

Rossman · March 2015

When the compressor in our freezer starts we will get a noticable flicker in our LED lights and you can hear the XW surge up to handle the startup. Am wondering if I can solve the flicker by implementing a motor start capacitor on the freezer? It's a new, energy star model upright freezer, aside from the draw on start it doesn't use much power. If it matters the freezer came with a service wiring diagram which I expect would be useful for any modifications.

I get the flicker whether running on XW only or with my Honda 7000W generator running, so I am not sure if it may be indicative of another issue.

Thank you for any and all advice!
-mark

BB. · March 2015

Try running an extension cord from as close as you can to the XW from the freezer (sub panel/AC outlet) to the XW. Does the separate home run from the freezer reduce LED brightness changes. That would help confirm that the XW regulation is OK. Also the extra extension cord could limit surge current some (100' 14 awg or smaller cord would have higher resistance than your branch circuit--This could reduce the peak starting current from the freezer).

If you have "one wire run" from the XW to the freezer + LED lighting (for example), you could be seeing wiring voltage drop from the freezer affecting the LED lamps.

Also try different LED lamps... Some may be more sensitive to voltage changes than others.

Check that you don't have any lose AC connections (breaker screws, wire nuts, outlet binding screws, etc.). Make sure there are not browned/burned/corroded wiring connections (I had a water leak that dripped down on a wire to a breaker in my old home).

-Bill

SkiDoo55 · March 2015

I think first I might try a different brand of LED lamp bulb in one of the fixtures that is having the problem. Ones you have may just be sensitive to any noise on the circuit. Would then check for any loose terminal connections from inverters/generator feeds to an from the distribution panel. Can try and isolate to a specific branch unless it is happening to multiple branches C/B's. Then work backwards to the inverter output feed.

BB. · March 2015

I had an outdoor security/motion detector fixture that I put in two CFL bulbs in. Because of the white wall/trees/fence near by, When I first aimed it, it turned out at dusk the fixture would turn on/off a few times a second. That was enough to cause flickering in the CFLs in the rest of my house (I had just started my CFL conversions at that time).

And my house was "on grid"--And the security lights were on different circuits vs the house wiring... It was really amazing how that flickering pair of CFLs cause the rest of my CFLs to flicker.

Re-aimed the lights, and all was well again.

-Bill

Rossman · March 2015

Freezer is right now on it's own, dedicated 12AWG run/20A breaker at the panel. All connections seem good/tight/no arcing. I have mostly all Cree 60W LED but I do have another Sylvania LED I will keep an eye on, but I only have about light 12 bulbs, on 3-4 different circuits. I do not have any kind of security or motion lights, it just seems to be the freezer. The companion fridge unit doesn't seem to have the same effect.

Thanks again for your kind replies!

RCinFLA · March 2015

Unless you have a very large freeze the start surge current is 8 to 15 amps maximum on 120vac and the XW6048 should not have a problem with that. Some LED light are sensitive to slightest glitch on the AC line. Another thing you might want to check is your balance between L1 & L2 loads on XW output. Maybe most of the 120 v loads are on one side of the output. You might try moving the freezer breaker in panel to other side (L1 to L2 or vice-versa). Generally the 120v breakers in breaker box jump L1-L2 sides every successive vertical location.

Starting motors is a trade off of time versus current. You draw a high surge for short period or lower surge for longer period. The start winding in a compressor is smaller diameter wire so increasing the starter cap value can put extra stress on winding. Lowering the value will lengthen the time for compressor to come up to speed. There is also initial mechanical load to consider. Just about all compressor will not start up with full head pressure of the Freon and must wait some period for pressure to equalize. This is typically done on refrig' by a thermistor that when load is too much it gets hot and mechanically trips a self resetting breaker that take about 15 to 30 minutes to re-engage.

In short, I would not mess with starting cap as you can do damage to compressor if you change the startup config too much.

Rossman · March 2015

I'll have to try some more LED bulbs. The freezer is nothing special, just a standard upright freezer, brand new, energy star compliant. Honestly the flicker doesn't bother me much as it only happens a couple times a day, I guess I just wanted to make sure it's not indicative of a system setup issue.

Thanks again for your reply.

H2SO4_guy · March 2015

My lights flicker when refrigeration or air compressor comes on. I am just learning to live with it, but it is annoying. I have noticed the same behavior in lighting in folks on grid. I think it is just the voltage sag affecting the lighting. It is brief in either case.

Dave Angelini · March 2015

If you have a good installation and you see the same results with different bulbs, you probably are going to have to get use to it. There are inverter based refrigeration systems that will be out that will end the surging as the inverter based heat pumps have for conditioning rooms
.Nice system, I have done a few like that with just one of the XW-80-600V controllers. They will current limit the input and the times that will happen are few. A nice cool location like yours (I would think) and you could keep the second unit as a spare. You will not need it as a spare as they can take it.Good Luck!

If you are using a dimmer, try removing it.

Rossman · March 2015

Dave Angelini wrote: »

Nice system, I have done a few like that with just one of the XW-80-600V controllers. They will current limit the input and the times that will happen are few. A nice cool location like yours (I would think) and you could keep the second unit as a spare. You will not need it as a spare as they can take it.

I was going to run 13x 250W panels wired in series directly into each CC... Thought I would rather have more amps to charge my battery bank, since I am entirely off-grid and winter days can be short.

I do not have any dimmers on the lights, just normal switches.

Rossman · March 2015

It may also be worth noting that I don't get this issue when our well pump kicks in, but it's a 240VAC Grundfos "soft start" deal. It's the only other reasonably large load we have connected right now.

BB. · March 2015

If some lights dim while other brighten, you could have a weak Neutral Connection somewhere. 240 VAC appliances don't use the neutral (for heavy current) and would not affect a poor neutral (120 VAC) connection to lights.

-Bill

Dave Angelini · March 2015

BB. wrote: »

If some lights dim while other brighten, you could have a weak Neutral Connection somewhere. 240 VAC appliances don't use the neutral (for heavy current) and would not affect a poor neutral (120 VAC) connection to lights.

-Bill

The wiring must be correct for sure! The other thing you can try is moving the lights that are flickering during the frige start-up to the other 120 vac leg.I would say that I have seen this before on too many installations and an inverter reefer is the solution as was his grundfos SQ.

Rossman,The reason I over solar a charge controller for offgrid is the max amps are rarely being current limited offgrid. The few extra amps that are lost is rare as most offgrid applications never use the power anyway. Especially in large systems like this. You will see this soon! Either way, not a problem. The best way would be to have an SE and SW array if you think you might benefit from longer sun hours(peak power at the extremes of the day) in which case you should use both controllers. Probably not a big issue where you live. It certainly is where I live in the Southwest US. Good Luck!

mike95490 · March 2015

I've found my XW-6048 to be quite the beast. 2 fridges and a freezer, 250' run from inverter shed to house. Only saw flicker when the "Meter Socket"contact springs went bad. Only thing I can think of is the battery circuit (batteries or wires) has some resistance and starves the inverter at high surge conditions.

Rossman · March 2015

mike95490 wrote: »

I've found my XW-6048 to be quite the beast. 2 fridges and a freezer, 250' run from inverter shed to house. Only saw flicker when the "Meter Socket"contact springs went bad. Only thing I can think of is the battery circuit (batteries or wires) has some resistance and starves the inverter at high surge conditions.

Interesting, yeah I am surprised I get any flickering on the XW, I didn't think that would happen. I guess I will recheck everything once again and make sure I didn't miss anything. Thanks!

Rossman · March 2015

Dave Angelini wrote: »

I would say that I have seen this before on too many installations and an inverter reefer is the solution

What's an "inverter reefer"?

I'd love to have a SW and SE array, but I guess I would have to change how I planned to set up my racks. As I haven't done that yet, perhaps a possibility. Honestly I will just be happy when I get the racks set up and get some power coming in from the PV so I don't have to use only my generator to recharge.

BB. · March 2015

I believe he is speaking of an Inverter Refrigerator... Instead of using a standard induction motor + compressor, they use a VFD (variable frequency drive) or an "inverter" to drive the compressor.

This gives "soft start" and variable RPM for less surge current and more efficient operation.

Digital Inverter Compressors

-Bill

sub3marathonman · March 2015

This might be worth a try, if for no other reason just as an experiment.

I'm wondering if the freezer can be plugged into an APC SmartUps 750xl or larger uninterruptible power supply and then see what happens.

During the power outages here in Florida after the hurricanes in 2004, I was able to power a refrigerator for days using the SmartUPS 750xl. I was able to go to my In-Law's house to recharge the UPS, and bring it back home to keep the refrigerator going. I needed to keep my mom's going too, but couldn't because it wasn't Energy Star and the startup surge would trip the UPS.

Rossman · March 2015

BB. wrote: »

I believe he is speaking of an Inverter Refrigerator... Instead of using a standard induction motor + compressor, they use a VFD (variable frequency drive) or an "inverter" to drive the compressor.

This gives "soft start" and variable RPM for less surge current and more efficient operation.

Digital Inverter Compressors

Ah right, of course. Well we just bought this fridge / freezer combo so buying a new unit is off the table. I will keep this in mind for the future, though.

sub3marathonman wrote: »

I'm wondering if the freezer can be plugged into an APC SmartUps 750xl or larger uninterruptible power supply and then see what happens.

Interesting suggestion, I actually happen to have an APC UPS around here somewhere I could connect. I'll put this on my list of things to try! Thanks!

lindsley · May 2015

I have a similar issue with my XW4024 and have accepted it as how it works. Had the same deep when I used the older SW3024. I have deduced that its either the battery (used forklift units) or the wire size to the Inverter. Will need to up to 4/0 and see how that changes.

Lights flicker on XW6048 when freezer starts

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