standby issue for silcon UPS

[Anonymous user]

hi guys

Need your expertise for my concern,
2 silcon 40kva UPS was connected in parallel, i switch off the Q1 of 1 of UPS so that it will run thru battery., but why the display show "standby" and the load was transfer to the other UPS. Any one can give me an explanation for this. Thanks in advance

[Anonymous user]

hi guys

Need your expertise for my concern,
2 silcon 40kva UPS was connected in parallel, i switch off the Q1 of 1 of UPS so that it will run thru battery., but why the display show "standby" and the load was transfer to the other UPS. Any one can give me an explanation for this. Thanks in advance

[upsguy_apc]

The silcon won't work this way. Its not a double conversion UPS, its delta conversion. Due to the nature of Delta Conversion both UPS would have to have their inputs open at the same time in order for them to run on battery as a test.

[Anonymous user]

its really make sense at all, now i understand already... thanks a lot. hope to hear from you soon for another issue..thanks again

[upsguy_apc · Accepted solution]

Yes this is way the UPS is supposed to operate. In delta conversion the UPS is online with utility actually flowing through the UPS to the load. If you were to take away utility to the UPS the main inverter would then need current from the battery to power the load. However since there are two UPS in parallel you can't have the main inverter trying to power the load with battery current and utility through the other UPS. This would result in an explosion since the main inverter output is a seperately derived source of power from the utility source in the other UPS.

Sorry if this doesn't make since... you really have to understand delta conversion to understand what I'm talking about.