How do you plan to step the loads separately? If they are all on the same bus the generator will see them on transfer regardless of how many steps you put in the software without additional controls.
What is the sKVA on the single step load results? Is the sKVA large, driving the size of your generator up well above the running load or is the gen. sizing result the same same approximately as your load calculation and running kW result? If the latter, not much reason for stepping the loads. Generally only with large and/or high quantity of motors (6x FLC inrush software likely approximates) are you going to have a large sKVA requiring the need for multiple steps.
To step the loads separately, you could:
- have 2 panel boards each supplied from its own respective ATS and set transfer time on one ATS 10s longer than the other (or any variation of similar arrangement)
- Interlock pilot control circuit of any large motor loads you have with timer delay to not allow start until after 10s upon power up
Both of these options will add cost so probably best to avoid stepping unless you have a large starting kVA for single step. One freebie may be to look over any large HVAC unit user manuals that will be on site as sometimes you will find they have a programmable or preset startup delay of about 30s or other duration upon power up. If they have this, you could input this equipment as a separate step and reduce your sKVA.
