LightWright Auto Balancing Issues

[Dylandtech]

So I am using Lightwright 5, and when I go to auto balance my phases, its not doing it properly, or so I believe.

Example:

Phase A: 206A

Phase B: 159A

Phase C: 154A

Is there a reason LW is having more Amps on Phase A than B and C? Or is it an error by the program?

Thank you-
Dylan

 

[xander]

Do you have the Systems set up properly? What kind of loads are you using?

 

[alexanderjoseph]

Sorry if this sounds rude, but why not going the easy way and ask John himself?
http://www.mckernon.com/cgi-bin/BugRep2/lwbugrep2.cgi

 

[SteveB]

So I am using Lightwright 5, and when I go to auto balance my phases, its not doing it properly, or so I believe.

Example:

Phase A: 206A

Phase B: 159A

Phase C: 154A

Is there a reason LW is having more Amps on Phase A than B and C? Or is it an error by the program?

Thank you-
Dylan

This is a question that's completely impossible for us to answer as we have no clue(s) as to your types of units and wattages, dimmer loading, dimmer types, phase assignments, etc....

Some thoughts;

In LW you can set up the Dimming and Control systems to tell LW what type of dimmers, capacities, phase assignments etc...

Just for fun, I just did the phase assignments for my Sensor dimmers. LW allows you to call up a Phase Template which you can use to automatically assign dimmers to phases. The template for an installed Sensor SR48 knows that dimmers 1&2 are A phase, 3&4 are B phase, etc.... Using that on my rep plot I got loading of between 147, 170 and 174 amps per phase on one rack. The other racks were equally unbalanced but as the layout of the dimmer circuits is a given as is the type of units on those dimmers, I would never bother using auto-balance as it's not really designed for this application.

What it can do is allow the electrician to assign the units to dimmers in such a method as to avoid imbalances. In a permanent system, it has no application as presumably the dimmers are laid out in a logical manner that makes sense to the users.

In a portable configuration, you could theoretically patch multi-circuit or individual cable home-runs to whatever dimmers the patch sheet generated by the auto-balance report tells you so as to avoid, as much possible, the imbalance. I've never heard of anyone doing this, but possibly someone (Rochem) could chime in and let us know if it's common practice.

 

[danTt]

I find that autobalance is less helpful in theater (when it's difficult to predict what systems of light will be on when) than it is with events (when a lot of times all lights are all on consistently. The balance goes out the window as soon as you have a cue that only has your blue high side system on, and not your amber... unless you balance with that in mind. That being said, I do try and get my phases close on portable racks, just to start from a sane position. I notice lightwright having issues with autobalance if you have any loads that do not have a wattage assigned, it quickly gets confused. Otherwise, it tends to come close for me consistently.

 

[MikeJ]

Load balancing with dimmers is somewhat of a moot point. As pointed out above, especially in theater the dimmers in use vary wildly throughout a show. And hopefully installed with phases distributed evenly throughout the space. With moving lights it is more accurate because of the constant load, although again with LED the load can change drastically.

Unless you are running very close to the limits of your power service, or are running on a generator(where a large imbalance can be a real problem), getting close will be fine.

In your example the results are not really that unbalanced, Just one 5k Fresnel could account for most of the extra current on A. If you added 2 more 5Ks, they would likely fall on B&C; back in balance. I know this might not be the case, but the point is that it is not a variation that is out of the realm on normal applications.