This was discussed here several years ago but I didn't see a clear answer.

We are dealing with complex systems that require evaluation for multiple operating scenarios (transfer switches, tie breakers, etc.). We currently use SKM Powertools, as is required by some of our clients. SKM is not capable of running multiple scenario systems with reduction mode active (confirmed by their support group). Currently I have to say that we have no way to produce incident energy calculations for arc energy reduction mode.

How are others handling this? Are there any other software packages than can run worst-case scenarios in arc energy reduction mode?

Thanks,

Unless I'm misunderstanding I don't know why you couldn't model two main breakers in parallel, one with the normal settings and one with the maintenance mode settings and put the MM breaker out of service in the base scenario and the normal settings out of service in the MM scenario. No scenario would have both main breakers in service at the same time.

Example. Base MCB is normal operating condition. MM MCB is maintenance mode operating condition.

One other thing, on new designs, I've often found that maintenance mode doesn't help much or any at all. Especially if the construction of the switchboard or panel is such you have to use the line side of main for the IE calc.

Even if the main section is barriered or you are using ArcBlok technology or other technology maintenance mode often won't help much unless you have built-in delays in your instantaneous setting on your main in normal operation for coordination reasons.

Of course, there are nearly unlimited scenarios possible with different types of construction and mitigation techniques and coordination requirements. Sometimes maintenance mode may indeed help a lot.

Incidentally, some engineers use this same methodology to analyze the available fault current from the utility. You can do it this way or change in each scenario in the Scenario Manager or a combination both. I like doing it this way sometimes (depending on what I'm analyzing) so I can see the effect of one vs. the other very quickly without having to leave the base model and go to each scenario.

For example: Infinite bus, Nominal from Utility and Minimum from Utility with Nominal in service and the other two "off":

Thanks for the input on this. I had not thought about creating a separate set of breakers with maintenance mode settings. That's not a bad idea if there is just one or a few. At a minimum it will double the number of scenarios that have to be analyzed. The systems I'm dealing with have numerous breakers with maintenance mode capability. They are connected to a central control system that enables MM for all breakers concurrently, or they can be controlled locally, individually. As you mention that seems to create a nearly infinite number of permutations. We could just run the case where they are all in maintenance mode I suppose.

Agree. It doesn't help for the equipment with MM setting where you have to consider the line side, just downstream.

That's what I would do (all Base scenario vs all MM). I don't know the particulars in your case but I don't label maintenance mode. That scenario could in the report that resides in the facility managers office. It's likely only one downstream panel or switchboard will be undergoing energized maintenance at a time, I would guess. The boss can look at the report and tell them what PPE is required if they flip the switch to MM.

So maintenance mode is optional?
I would expect that maintenance mode for live work would be a safety requirement subject to disciplinary action if not followed. I would suggest one label with the maintenance mode incident energy and and with the words maintenance mode clearly stated. Don't forget that overdressing for the worst case IE is not necessarily safer.