Homage UPS Disassembly

After one year of Homage UPS usage I tried to self service it and during process I took some high resolution images for those who want to take an inside look , For all images you may visit my blog

http://khurram4m.blogspot.com

THe image when I first purchased it back in May 2012

And After One Year June 2013

After Cleaning

Looks nice, I might replace my digitech with homage ups, What are their charging amps?

[quote=“djayz, post:3, topic:19620”]

Looks nice, I might replace my digitech with homage ups, What are their charging amps?

[/quote]

As per Manual it is 10 Amp (+/-1 amp)

Anyone here who can provide some information what is function of those two transformers shown in Homage Circuit???
In local desi type UPS One transformer is small and other is always a Huge one, But here we see a very tiny transformer is it good or bad???

@OP,

no offence, but

Did you buy this ups or dig it up in some sandstorm? :wacko: :wacko: :wacko:

[quote=“farhan_ds, post:6, topic:19620”]

@OP,

no offence, but

Did you buy this ups or dig it up in some sandstorm? :wacko: :wacko: :wacko:

[/quote]

haha well it happens Farhan after using it for some months because of heavy load shedding its fan will always on. I recommend to clean it with blower after every 3 4 months. Soon the fan will become noisy and need to be replaced. :)

[quote=“uzair82, post:7, topic:19620”]

haha well it happens Farhan after using it for some months because of heavy load shedding its fan will always on. I recommend to clean it with blower after every 3 4 months. Soon the fan will become noisy and need to be replaced. :)

[/quote]

Exactly , But how can you clean it every 3 months in first year of purchase it will void its warraty

(Though the so called warranty has no worth in Pakistan for domestic User :) )

[quote=“khurram4m, post:5, topic:19620”]

Anyone here who can provide some information what is function of those two transformers shown in Homage Circuit???

In local desi type UPS One transformer is small and other is always a Huge one, But here we see a very tiny transformer is it good or bad???

[/quote]

There are two ferrite core transformers, one is big one lying horizontally and the other is smaller one which is mounted vertically.

The big one converts the battery voltage (12 or 24 DC) into a high voltage DC (something like 305-315V DC) at a high frequency (about 100KHz or even more). That is the reason it is able to handle a power of 1KVA or even 2KVA since it operates at high frequency.

In the next step this high voltage DC is chopped to produce a PWM AC (also called near sine wave or modified sine wave) to produce the AC output.

The smaller transformer is for charging the battery. Input AC 220V is converted to DC and then stepped down to charge the battery. Once again, this transformer also operates at around 100KHz so the size is small.

[quote=“uzair82, post:7, topic:19620”]

haha well it happens Farhan after using it for some months because of heavy load shedding its fan will always on. I recommend to clean it with blower after every 3 4 months. Soon the fan will become noisy and need to be replaced. :)

[/quote]

If this fan slows down due to friction by accumulated dust, the trapped heat inside, could blow up the inverter or the charger ( whichever was working at the time of disaster).

^ The fan is supposed to be on during charge? My desi UPS units always charge with the fan off

It should be actually based on internal temperature and fan RPM should also be under the control of internal circuit so that heat can be very quickly removed when required.

I have seen that some models run the fan only during charging and some keep the fan running both in inverter and charger mode with few models turning on the fan when necessary.

[quote=“khurram4m, post:8, topic:19620”]

Exactly , But how can you clean it every 3 months in first year of purchase it will void its warraty

(Though the so called warranty has no worth in Pakistan for domestic User :) )

[/quote]

cleaning should not be done with a water hose pipe,,, a simple air blower will clean 90% of dirt without even opening the unit.. the best direction is to blow the exhausts fans and the power unit thoroughly, because as ijaz said, these areas accumulate most dust,.. also i find that the dirty fans also produce the most noise.. cleaning with unit case cover wont void your warranty, untill you rip off some seals or sticker which clearly say warranty void.

[quote="executionist, post:11, topic:19620"]

^ The fan is supposed to be on during charge? My desi UPS units always charge with the fan off

[/quote]

when battery starts charging at higher amps, say after wapda resumes, then fan should run at full speed as lots of heat energy is being produced.. as battery ca=harges up and amps drops, then rpm may decrease in proportion with the heat decreased.... on full charge, fan runs very very slow, almost inaudible..

if your unit starts to heat up after 15 min of wapda back, then look at the fan behavior closely.. if you are skilled enough, you can dismount wash the fan in surf water for 15 min, air blower dry and lightly oil the fan borders with sewing grade oil, your fan should run optimally at full speed and very low noise..

i do that every 6 months with my PC PSU fan.. noise comes down from harley davidson level to low level phook quite..

[quote=", post:9, topic:19620"]

There are two ferrite core transformers, one is big one lying horizontally and the other is smaller one which is mounted vertically.

The big one converts the battery voltage (12 or 24 DC) into a high voltage DC (something like 305-315V DC) at a high frequency (about 100KHz or even more). That is the reason it is able to handle a power of 1KVA or even 2KVA since it operates at high frequency.

In the next step this high voltage DC is chopped to produce a PWM AC (also called near sine wave or modified sine wave) to produce the AC output.

The smaller transformer is for charging the battery. Input AC 220V is converted to DC and then stepped down to charge the battery. Once again, this transformer also operates at around 100KHz so the size is small.

[/quote]

Thanks for replying and what about Desi type UPS with a huge transformer (even for 500Watt) as compare to this small one in Homage ???

[quote=", post:12, topic:19620"]

It should be actually based on internal temperature and fan RPM should also be under the control of internal circuit so that heat can be very quickly removed when required.

I have seen that some models run the fan only during charging and some keep the fan running both in inverter and charger mode with few models turning on the fan when necessary.

[/quote]

We don't see any fan in APC UPS upto 750VA and its fully covered as well, how do they handle this heat problem??? is there any alternate to fan ???

APC never designed ANY UPS for load shedding. With it's internal battery, the APC can run for few minutes only. So there is not much heat inside. Also they have good quality transformers and low loss components thus eliminating the need for a forced convection.

[quote=“khurram4m, post:14, topic:19620”]

Thanks for replying and what about Desi type UPS with a huge transformer (even for 500Watt) as compare to this small one in Homage ???

[/quote]

The difference I already explained is due to the operating frequency. In local made UPS, the transformer operates at 50Hz thus very big and iron core, while in these inverters the transformer operates at very high frequency (around 100KHz) so it's size is very small for the same power rating.

[quote=", post:16, topic:19620"]

APC never designed ANY UPS for load shedding. With it's internal battery, the APC can run for few minutes only. So there is not much heat inside. Also they have good quality transformers and low loss components thus eliminating the need for a forced convection.

[/quote]

Many Thanks brother for replying I understand now

APC does have developed Home applience UPS but unfrotunatly it is not avaliable in Pakistan it is actually Indian version see here

http://www.apc.com/products/family/index.cfm?id=321

Specs looks great Pure Sign wave and looks great and cost 16000 pak rupees before buying Homage I contacted many authorised APC dealers for arranging this Unit even used my professional contacts but there import channel is singapore and it wasn't avaliable there

321_fam.jpg

58227DC4-5056-9170-D3DE5AF34C0823DB_pr.j

[quote=", post:17, topic:19620"]

The difference I already explained is due to the operating frequency. In local made UPS, the transformer operates at 50Hz thus very big and iron core, while in these inverters the transformer operates at very high frequency (around 100KHz) so it's size is very small for the same power rating.

[/quote]

Then why don't desi ups use 100 KHz transformer ??? coz local shops using off the shelf chinese kits so why that heavy bulky Transformer? When I contacted one of Desi UPS manufacturer he was ephasising this huge size and told me Homage UPS use tiny transformer which heat up quickly and burns very often, I mean Transformer size was his selling point, Is it correct or he was just bluffing :mellow:

[quote=", post:, topic:"]

http://www.apc.com/products/family/index.cfm?id=321
[/quote]

that apc model

it is NOT pure sine wave.. modified square wave.. thus the low price.. and very low power handling,..500Watts only.. plus dont expect charging to be more than 10 amps peak..