Help on Inverter/UPS

[arnprasad]

Hi all,

I have an Exide inverter/UPS setup at ground floor. Its a 1050VA @ 85% efficiency..so practically around 700 watts of usable power. I have my entire plug points/Switches split into UPS and non UPS. All heavy duty ones like fridge/washing machine..,..etc are in non UPS setup.

I have bought a second UPS and battery and having it installed in first floor. Now the UPS has two modes..in Luminous the first mode is called ECO which is basically bypassing UPS and hence in case of a power failure it takes around second for UPS to start functioning and hence not suitable for office working/desktops. The second mode is the UPS mode where power always goes via the inverter and in case of mains failure, we don't notice a difference.

Now my electrician is telling me that there is no need to split all my first floor plugs and switches into UPS and non UPS. He says even if UPS is rated for say 700 watts as long as we have mains power - even if I use heavy duty appliances like microwave and convection oven - it shouldn't matter and they will work. Only when the mains is off, it will show as overload and shut off. I don't think this is how inverters work, particularly in UPS mode. Please advice. I need this clarification since he is installed it yesterday and he is still around today and if I cannot use my ovens when the mains are on - I need him to make 5A/15A sockets as non UPS ones like in ground floor.

Below are the questions again:

(a) in "Eco" mode on my inverter of say capacity of 700W - Can I run appliances totaling say 2000 W when the mains are on? I believe the answer is yes, because I did have all the lights and fans and both my ovens on yesterday and they all worked. However this mode is a problem for me because there are desktops and routers which need uninterrupted supply...hence point 2 below
(b) To suit the needs of routers and computers - if I have the inverter in UPS mode - even when mains are on - Can I run appliances totaling more than 700 watts?

I tried googling - but framing this question is very difficult and the only answers I got was differences between UPS and ECO modes.

 

[zeta148]

check the UPS fuse rating (or nowadays they come with MCB) - if it 5A, then won't the UPS MCB trip if there is more than say 230*5A~1000w drawn even with mains power available? Not 100% sure but just thinking the MCB will trip since electricity--regardless of whether there is mains electricity or not--from the UPS should flow through the MCB

 

[ajuvignesh]

I have a v-guard Inverter and it shuts down if a vacuum cleaner is connected to an UPS line. You better call luminous before making changes to your wiring setup.

 

[VRavichandar]

Hi all,

I have an Exide inverter/UPS setup at ground floor. Its a 1050VA @ 85% efficiency..so practically around 700 watts of usable power. I have my entire plug points/Switches split into UPS and non UPS. All heavy duty ones like fridge/washing machine..,..etc are in non UPS setup.

I have bought a second UPS and battery and having it installed in first floor. Now the UPS has two modes..in Luminous the first mode is called ECO which is basically bypassing UPS and hence in case of a power failure it takes around second for UPS to start functioning and hence not suitable for office working/desktops. The second mode is the UPS mode where power always goes via the inverter and in case of mains failure, we don't notice a difference.

Now my electrician is telling me that there is no need to split all my first floor plugs and switches into UPS and non UPS. He says even if UPS is rated for say 700 watts as long as we have mains power - even if I use heavy duty appliances like microwave and convection oven - it shouldn't matter and they will work. Only when the mains is off, it will show as overload and shut off. I don't think this is how inverters work, particularly in UPS mode. Please advice. I need this clarification since he is installed it yesterday and he is still around today and if I cannot use my ovens when the mains are on - I need him to make 5A/15A sockets as non UPS ones like in ground floor.

Below are the questions again:

(a) in "Eco" mode on my inverter of say capacity of 700W - Can I run appliances totaling say 2000 W when the mains are on? I believe the answer is yes, because I did have all the lights and fans and both my ovens on yesterday and they all worked. However this mode is a problem for me because there are desktops and routers which need uninterrupted supply...hence point 2 below
(b) To suit the needs of routers and computers - if I have the inverter in UPS mode - even when mains are on - Can I run appliances totaling more than 700 watts?

I tried googling - but framing this question is very difficult and the only answers I got was differences between UPS and ECO modes.

I had a similar wiring earlier - the plug points were not separated into inverter / non-inverter. Every time the power went off and the washing machine was running, it used to 'trip' the inverter due to overload causing all inverter output to shut off. This needed a manual reset after switching off the offending equipment to bring it back online. This was like having a sudden power cut - defeating the purpose of having an inverter. I use a 5+year old luminous inverter model. You may have to check what is applicable for your model.

a. Devices that have a high starting current - especially equipment with motors such as washing machine, mixer, drill machine (in my real life experience) cause the overload trip in the inverter. I would be vary of using the inverter in the way you have described.

b. The total load that you can run would depend on the inverter rating plus also the installed battery capacity (Ampere Hours).
Luminous says for its Zelio inverters
"You can set it to High Power mode in order to run appliances that have a higher load than the capacity of the inverter. You can also optimise the inverter output for better back-up or higher performance".
This means - you get more backup time with lower loads and less backup time with higher loads.

Hope this helps!

 

[arnprasad]

Hi. Thanks for your response. I saw it a bit late. My electrician suggested that I just buy a second UPS for my first floor which I did..Zolt 1100. So now I have two separate UPS and batteries for both floors and also few of 15/5amp plug points he has made it non Inverter. So it works for now.

I got a new problem. My RCCB which is 30mA trips many times a day. Used to trip couple of years ago also - so as a stop gap measure electrician then had directly connected the mains wires skipping my RCCB. Not sure if it was a smart move as I completely forgot about it and also in these two years there were no incidences of any major electric shocks. As part of the ongoing repairs, where I am replacing MCBs and RCCBs, my new electrician noticed and reconnected the RCCB with a result that 3-4 times a day it trips and we have to manually go and turn it back up. This tripping doesnt happen when I switch on a particular switch or device and hence it is difficult to pinpoint what exactly is causing it. Hoping he comes up with a solution soon and I too am searching for solutions on the net without much success. If any of you have any expert opinion on this with solutions...will be greatful

 

[VRavichandar]

Hi. Thanks for your response. I saw it a bit late. My electrician suggested that I just buy a second UPS for my first floor which I did..Zolt 1100. So now I have two separate UPS and batteries for both floors and also few of 15/5amp plug points he has made it non Inverter. So it works for now.

I got a new problem. My RCCB which is 30mA trips many times a day. Used to trip couple of years ago also - so as a stop gap measure electrician then had directly connected the mains wires skipping my RCCB. Not sure if it was a smart move as I completely forgot about it and also in these two years there were no incidences of any major electric shocks. As part of the ongoing repairs, where I am replacing MCBs and RCCBs, my new electrician noticed and reconnected the RCCB with a result that 3-4 times a day it trips and we have to manually go and turn it back up. This tripping doesnt happen when I switch on a particular switch or device and hence it is difficult to pinpoint what exactly is causing it. Hoping he comes up with a solution soon and I too am searching for solutions on the net without much success. If any of you have any expert opinion on this with solutions...will be greatful

To put in simple terms, RCCB works by comparing the current on the phase wire to the current on the neutral wire. These two should be equal. If there is any variance, RCCB will trip.
By-passing an RCCB is not advisable at all - it trips only when there is a fault. In an electric shock - current is flowing to the ground through your body. 10mA of residual current passing through a human can evoke a prickling sensation where as higher values can cause muscular contraction, leading to a respiratory paralysis. RCCBs cut off the power supply in such cases (at 30mA residual current)
RCCBs trip whenever there are sudden changes in electrical load, there can be small current flow to earth especially in old appliances.
If switching on a device is not causing the RCCB trip, then changes that happen when an equipment is in operation causes it. List all equipment that was running at the time of trip. Start by isolating these one by one. Likely culprits are washing machines, air conditioners, microwaves, electric kettles, toasters, Hair appliances, fridges and freezers, vacuum cleaners etc - anything that has a variable load or transient in operation.
Even faulty wiring, poor tightening of terminals, poor contact between plug and socket are known to cause such trips. Requires painstaking work to sort out the issue, but worth it.

 

[Shanmugam]

Better check if your ground earth pit is in good condition

 

[arnprasad]

To put in simple terms, RCCB works by comparing the current on the phase wire to the current on the neutral wire. These two should be equal. If there is any variance, RCCB will trip.
By-passing an RCCB is not advisable at all - it trips only when there is a fault. In an electric shock - current is flowing to the ground through your body. 10mA of residual current passing through a human can evoke a prickling sensation where as higher values can cause muscular contraction, leading to a respiratory paralysis. RCCBs cut off the power supply in such cases (at 30mA residual current)
RCCBs trip whenever there are sudden changes in electrical load, there can be small current flow to earth especially in old appliances.
If switching on a device is not causing the RCCB trip, then changes that happen when an equipment is in operation causes it. List all equipment that was running at the time of trip. Start by isolating these one by one. Likely culprits are washing machines, air conditioners, microwaves, electric kettles, toasters, Hair appliances, fridges and freezers, vacuum cleaners etc - anything that has a variable load or transient in operation.
Even faulty wiring, poor tightening of terminals, poor contact between plug and socket are known to cause such trips. Requires painstaking work to sort out the issue, but worth it.

Thank you. Even I read something similar on the internet. My electrician said he will try and fix it.. Hope it works. Thanks again for your response

 

[arnprasad]

Better check if your ground earth pit is in good condition

Yeah.. That is one of the ideas.. This is an old house and we have done many electrical modifications. Hope my electrician finds his way out.