Hey all,

 

So I have a question, I would ultimately like to have multiple inverters in parallel, I would also like to install a bit of protection like this device: https://www.snaga.co.za/product/automatic-voltage-protector-avp60-micro-protection-for-inverters/

 

I was planning on having each inverter fed from the main "Eskom DB" on separate circuit breakers, I was wondering would be advisable and ensure it is compliant with our local laws.

I was initially thinking perhaps I go for multiple, smaller AVP's (one per inverter), however one thing I am unsure of is if there are 2 or more inverters in parallel and they get power at different times (due to the time delay which is offered by the AVP). For example the "slave" inverter boots up before the "master" inverter - would this cause issues? These would be Luxpower SNA5000 inverters, if it makes any difference.

 

Then I was thinking to avoid the possibility of inverters starting up at different times and this being a problem and maybe keep things simple, opt for a larger AVP like the 60a one linked above and use that single AVP for both inverters, although that would mean if I had a circuit breaker for each inverter, I would be "combining" the outputs in the AVP and then output would once again be 2 wires... I am not sure whether this would be allowed and compliant? I assume not as if I turn the power off to the one circuit breaker, both inverters would still get power and this defeats the point of separate CB's?

 

Alternatively, do I just use a single, larger circuit breaker, feed this into the AVP and then have 2 cables coming out of the AVP powering both inverters? Once again, not sure if this would be compliant but at least if I turn the CB off both inverters lose AC power and they start up at the same time.

 

So basically, looking for a bit of advice and suggestion as to the best way to do this.

@Scorp007 @TaliaB @WannabeSolarSparky

Any advice you guys could provide?  

5 minutes ago, PsyCLown said:

@Scorp007 @TaliaB @WannabeSolarSparky

Any advice you guys could provide?  

Power it from the DB. Once the AVP allows a connection this connection is wired to your 2 MCBs feeding each inverter. 

Just remember the inverter already checks for stable incoming AC and frequency only then will it synchronize with Escom mains and then only go into bypass. These AVP units is more for appliances especially fridge compressors. I will rather fit SPD's if not fitted to your incoming mains before the inverter mcb's. If your inverter sees low voltage, high voltage or incorrect frequency it will not synchronize. Everbody is jumping on the bandwagon since inverters became popular very popular in SA even AVP.

24 minutes ago, TaliaB said:

Just remember the inverter already checks for stable incoming AC and frequency only then will it synchronize with Escom mains and then only go into bypass. These AVP units is more for appliances especially fridge compressors. I will rather fit SPD's if not fitted to your incoming mains before the inverter mcb's. If your inverter sees low voltage, high voltage or incorrect frequency it will not synchronize. Everbody is jumping on the bandwagon since inverters became popular very popular in SA even AVP.

What about inverters just passing the grid input(surge) straight via bypass to you loads? No filtering taking place. The the AVP has its merit is it not? It can protect non essentials if you use a say 80A version to protect the whole DB. Not all loads are fed from the inverter. 

Edited July 6, 20233 yr by Scorp007

4 hours ago, Scorp007 said:

The the AVP has its merit is it not?

To be honest i don't know these AVP units they haven't been around for long but what i am familiar with is automatic voltage regulators(AVR's) used to regulate and stabilize voltage fluctuations found in the voltage supply. This ensures a stable voltage output to the connected appliances. Depending on the AVR design, the adjustment in voltage can occur either through servo motor mechanism or a relay/transistor mechanism. I would actually like to open the AVP unit up and see exactly what is inside the circuitry would just be an expensive exercise. To protect the entire db without knowing the ka rating( fault current capability) of this unit will be dicey.

13 minutes ago, TaliaB said:

To be honest i don't know these AVP units they haven't been around for long but what i am familiar with is automatic voltage regulators(AVR's) used to regulate and stabilize voltage fluctuations found in the voltage supply. This ensures a stable voltage output to the connected appliances. Depending on the AVR design, the adjustment in voltage can occur either through servo motor mechanism or a relay/transistor mechanism. I would actually like to open the AVP unit up and see exactly what is inside the circuitry would just be an expensive exercise. To protect the entire db without knowing the ka rating( fault current capability) of this unit will be dicey.

Totally different products. You talk of a controller that adjusts the voltage all the time via a variac type auto transformer while the AVP will cut all loads off if outside the low and high settings to protect the equipment. 

A 60A AVR or stabiliser as some call it would cost quite a bit but they do work great. 

Edited July 6, 20233 yr by Scorp007