automatic switching of the power supply of the house from the UPS to the power station

Welcome,

i recently sourced an ups ( volt sinusPRO 700/1000W(S) ) with the possibility of connecting solar panels.

What are the options for a target power supply for the whole house from this device in a situation where the house works on a consumption of about 300W-400W ( TV, fridge + some electronic small things there ).

Specifically, what I have in mind is a fast switching system when someone turns on the kettle, microwave or boiler heater.

My idea is to use a current relay (e.g. EPP-619) to supply current to the coil of 2xNO+2xNZ contactors (+ possibly some kind of staircase switch to keep the voltage on the coil e.g. for 1 minute). ). Does this make sense? Will it work before the overcurrent fuses on the UPS blow?

Regards

I don't think there is any chance of the UPS working properly. Will this UPS be able to "pull" a fridge with a TV etc small appliances?
I would use separate circuits for smaller appliances with power from the UPS and separate circuits for washing machines, irons, kettles, ovens etc.
Even if the UPS by some miracle held up you would have the UPS disconnected under heavy load all the time causing quite a disturbance to the mains.
You can't use 4 contactors because if one stuck together the other would also trip and beautiful fireworks would ensue. The contactor would also have to be robust which will increase the cost considerably.

Jacek Rutkowski wrote:

There is absolutely no chance of the UPS working properly. Will this UPS be able to "pull" a fridge with a TV, etc. small stuff?

The rated power of the UPS is 700W, the peak power of 1000W is more than likely to "pull" it

Jacek Rutkowski wrote:

I would use separate circuits for lower wattage appliances with power from the UPS and separate circuits for washing machine, iron, kettle, oven etc.

This is how it works now. I have a separate UPS circuit on which the whole house control ( pumps, controllers, alarm ) hangs.
But the appetite grows with ..... That's why I'm considering somehow covering the whole house with it and dynamically switching the power station/UPS depending on the load.

Jacek Rutkowski wrote:

Even if the UPS by some miracle could withstand it, you would still have the UPS disconnected under heavy load causing quite a disturbance in the network.

well I am aware of this, how the receivers will react to an interrupted and jammed sine wave I take for myself. It seems to me that it is difficult to determine this otherwise than by "battle". I've already played around a bit with phase switching using a contactor and in general none of the computers switched off, on the TV there was a slight momentary distortion of the picture

Jacek Rutkowski wrote:

You can't use 4 contactors because if one gets stuck together, the other will also work and beautiful fireworks will ensue. The contactor would also have to be robust which will increase the cost considerably

the contactor will be one modular with 4 contacts:
http://ekatalog.legrand.pl/pl/produkt/004133.html

from the diagram it appears that in the event of a failure, all or none of the contacts will work.
But in the worst case scenario, i.e. selective contact bonding, I still have differential and overcurrent circuit breakers which will trigger immediately in case of an overload of the UPS or a short circuit of the UPS with the power plant.


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getting back to the point, I am most interested in whether:
the tripping time of the current relay + the switching time of the contactor < the tripping time of the overcurrent circuit breaker C10.

The FF EPP-619 relay has a minimum trip time of 0.5s, while the C10A overcurrent circuit breaker will withstand 50A for at least 1s which the UPS will definitely not withstand if it does not protect itself

it seems to me that some problems like switching times are solved by using electronic relays,
they are fast, strong enough for the power you are handling
in addition the use of those with zero-crossing eliminates other problems

IGS wrote:

I think that some problems like switching times are solved by using electronic relays,
they are fast, strong enough for the power you are handling
in addition the use of those with zero-crossing eliminates other problems

Unfortunately mate but a current relay will do nothing for 0.5s even if 100A is flowing and during that time the UPS will protect itself and there will be a power failure.

Good point about the switching time, some may have missed it
However, the switching time you mentioned is probably exaggerated, the standard SSR switching time is less than 10 ms
If this is not enough, you can use an SSR which can be switched on at any time, these are as fast as traditional relays with a time of less than 1ms, this is probably enough?

Unfortunately, it is not so much the speed of the contactor but the delay in tripping the current relay which forces a minimum of 0.5s delay in switching from the moment the load is increased (presumably to avoid transients in the first moment after the load is increased). No matter what key we use, there is still a minimum of 0.5s load after the overload is connected to the UPS.

the time <10ms is much less than 0.5 s
i am writing about the tripping time of the ssr relay itself, as a proposal instead of other switching elements
i have not considered the inertia time of the whole system