Possible Electrical Bug? How can Current Load Exceed Potential Load?

[John N.]

Can someone explain to me what is happening is this screenshot?

Every few game seconds my power grid, with a maximum potential load of 1200 / 2000 W  flashes to a current load of 2981 / 2000 W, burning out a random conductive wire.  I can add up the buildings drawing power, and they add up to 1200W. 

I guess I don't understand what "potential load" means, because it clearly is not a maximum possible load on the circuit...

Can someone explain how current load and potential load is calculated in ONI?  This may help me debug my base.

Thanks in advance.

John

[Urist McPilot]

This kind of thing happened to me when I accidentally connected both the input and output of a transformer to the same circuit. While the game calculated the potential load correctly, the transformer in the loop seemed to be multiplying the actual load.

[Destyn]

The thing is that transformers do not count as potential load, but they will be a load.
my reccomendation to avoid this is simply make a "central" heavy wire and connect all your power sources in it, and distribute via transformers to the places you need power

[nakomaru]

Indeed, not even the potential load is calculated correctly. Transformers are 1kW/4kW consumers.

[OxCD]

49 minutes ago, nakomaru said:

Indeed, not even the potential load is calculated correctly. Transformers are 1kW/4kW consumers.

Yup that has always been like this and depending on how your electric grid is set that could be really annoying.

[mathmanican]

Here is an addon to @nakomaru's reply.

Since transformer's don't count toward the potential load, but they do add to the current load, you can easily exceed the potential load. @John N., my best guess is that you have a transformer attached to this line, somewhere off the screenshot you gave us. 

 

[ZanthraSW]

Is that only the case when you have a battery on the other side? Batteries don't count as potential load, but do count as current load. Transformers should duplicate all their potential load to the upstream circuit, but won't display themselves as a potential load. If you put a normal load on the other side it should display properly on the upstream side.

I expect the overload condition is being caused by battery charging.

PS: Nevermind. I was wrong. Was not the first and won't be the last. Transformers don't report any potential load to the upstream wire. Steam does not have previous versions of ONI in the betas tab so I can't check if this was previously the case, but for some reason I thought it was.

[KittenIsAGeek]

On 7/24/2020 at 2:39 PM, ZanthraSW said:

Transformers don't report any potential load to the upstream wire. Steam does not have previous versions of ONI in the betas tab so I can't check if this was previously the case, but for some reason I thought it was.

I don't remember transformers ever showing their potential load to the 'high' side wire.  Transformers are a somewhat odd piece of equipment.  On the 'low' side they act as a battery that's always full (provided there's enough power on the high side), and on the high-side they appear as a power consumer when active.

It would be nice if the high side showed the potential load, but I can see how it might be problematic.  The potential load of the transformer is equal to the load of the down-line consumers, or its maximum rating, which ever is lower.  It may be that this was not working as intended, so the devs just turned off the potential load part of the code.  I do remember quite a few anomalies while using transformers, including the ability to feed a loop back through multiple transformers and power everything without a generator, so maybe removing the 'potential load' from the code on transformers was part of the fix.

 

**Edit: The low side of a transformer acts like a battery that is always full, provided there's enough power on the high side to refill it every tick.

[nakomaru]

2 hours ago, KittenIsAGeek said:

On the 'low' side they act as a battery that's always full

It used to be like this. The input was limited to 200J/tick or 800J/tick, but could be drained instantly (i.e. 1000J/tick or 4000J/tick on first tick). Due to the buffer, it could exceed its power rating in this way.

However, a few patches ago they changed it so that both input and outputs are rate limited. Now it can be fully thought of as a generator & consumer.

[TheMule]

13 hours ago, KittenIsAGeek said:

hey appear as a power consumer when active.

A variable power consumer. Contrary to all other loads, which have an on/off status, but it's either full load (e.g. 1200W) or zero, transformers are peculiar in that they "copy" the load on the low side to the high side, but it's not known in advance.

So what they should really do, in a perfect world, is copy also the potential load, capped up to their rating.

So a 1kW transformer with a potential load of 480W on the low side, should increase the potential load on the high side by 480W. The same transformer with a potential load of 3000W on the low side, should increase the potential load on the high side by only 1000W.

This causes that everytime you add a device to the grid, all potential loads should be updated. Maybe the devs decided against it, and transformers are just ignored.

 

Edit: TL;DR: what @KittenIsAGeek wrote. :P

[ZanthraSW]

 

19 hours ago, TheMule said:

A variable power consumer. Contrary to all other loads, which have an on/off status, but it's either full load (e.g. 1200W) or zero, transformers are peculiar in that they "copy" the load on the low side to the high side, but it's not known in advance.

So what they should really do, in a perfect world, is copy also the potential load, capped up to their rating.

So a 1kW transformer with a potential load of 480W on the low side, should increase the potential load on the high side by 480W. The same transformer with a potential load of 3000W on the low side, should increase the potential load on the high side by only 1000W.

This causes that everytime you add a device to the grid, all potential loads should be updated. Maybe the devs decided against it, and transformers are just ignored.

 

Edit: TL;DR: what @KittenIsAGeek wrote. :P

Although you would still have an edge case with the other variable power consumer, the battery. It also is not full load or zero. They strangely enough, don't produce any current load either. You can charge batteries at any rate you like using 1k wire without the wire overloading as long as no other consumers use more than 1k. On the other hand, if you are charging the battery through a transformer, the high does see power to the transformer as current and can overload the wire while the low side from the transformer to the battery does not and the wires are safe.

Additionally, while players generally build their power network as a tree structure, there is no technical prevention of loops besides the trivial one with a transformer plugged into itself. High side and low side have less meaning in this case, although currently with any loops it seems all the transformers in the loop are active at full load to the next transformer anyways, so in some ways it's simpler ;).

[nakomaru]

Sorry to repost myself - they are simply 1kW/4kW consumers and should be treated as such for potential load. Doesn't matter what's currently plugged in.

[ZanthraSW]

7 hours ago, nakomaru said:

Sorry to repost myself - they are simply 1kW/4kW consumers and should be treated as such for potential load. Doesn't matter what's currently plugged in.

Interesting. So right now it would be entirely accurate to just list them as 1k and 4k potential loads on the circuit. It also looks like there is a minimum duration that a circuit must be overloaded for in order to start doing wire damage, so only in some edge cases would transformers extra power draw be unsafe (which would make it more confusing when it does happen).