uninterrupted power supply {UPS} - switching mechanical relays with solid state

Thread Starter

sri harsha guthikonda

Joined Feb 5, 2017
7
i have many ups units..
iam planning on switching relays.

is that a good idea?

if so.. what are the limitations and what are the problems i am going to face?

iam a noob (actually a medical doc)..

thank u

any help appreciated.
 

schmitt trigger

Joined Jul 12, 2010
453
Make sure that the contact rating is adequate for the rated current and interrupting voltage.

If you show us a good close up photo of a sample relay, we can point out what ratings are important and why.
 

Thread Starter

sri harsha guthikonda

Joined Feb 5, 2017
7
Make sure that the contact rating is adequate for the rated current and interrupting voltage.

If you show us a good close up photo of a sample relay, we can point out what ratings are important and why.
actually i dint open the ups..because it running is very necessary . soon i will figure out a way to replace it and i will post that picture

tq
 

tcmtech

Joined Nov 4, 2013
2,867
More importantly to begin with, why do you feel you need to replace the mechanical relays with solid state?

What is the perceived justification and expected end gains in doing so?
 

Thread Starter

sri harsha guthikonda

Joined Feb 5, 2017
7
More importantly to begin with, why do you feel you need to replace the mechanical relays with solid state?

What is the perceived justification and expected end gains in doing so?
bcoz solid state operate faster..
because of huge voltage fluctuations wen my air conditioner (external unit) starts and stops my pc shuts down
and during that fluctuation i can hear the mechanical relay rattling
 

Thread Starter

sri harsha guthikonda

Joined Feb 5, 2017
7
More importantly to begin with, why do you feel you need to replace the mechanical relays with solid state?

What is the perceived justification and expected end gains in doing so?
bcoz solid state operate faster..
because of huge voltage fluctuations wen my air conditioner (external unit) starts and stops my pc shuts down..sometimes..
but most of the times..like every 2 hrs..or some..external hdds disconnect with the power fluctuations....and i can hear hdd seizures...these days...
and during that fluctuation i can hear the mechanical relay rattling
the relay doesnt rattle when i pull the plug and my pc doesnt shutdown...
 

MaxHeadRoom

Joined Jul 18, 2013
23,383
bcoz solid state operate faster..
because of huge voltage fluctuations wen my air conditioner (external unit) starts and stops my pc shuts down
and during that fluctuation i can hear the mechanical relay rattling
That is a more of a symptom of inadequate sizing of service supply conductors to each unit being fed.
If you have a AC relay coil that is being operated under voltage, and the armature is vibrating, it will eventually burn out.
Max.
 

MaxHeadRoom

Joined Jul 18, 2013
23,383
I am not in a position to accurately diagnose the problem, but if you are getting volt drop then I would think it is either the Capacity of your UPS or incorrect cable sizing.
Air conditioners are typical high current users when initially powered, it would be a case of local monitoring the voltage of the supply somehow and see what fluctuation exists in order to find the source and solution.
Max.
 

Thread Starter

sri harsha guthikonda

Joined Feb 5, 2017
7
I am not in a position to accurately diagnose the problem, but if you are getting volt drop then I would think it is either the Capacity of your UPS or incorrect cable sizing.
Air conditioners are typical high current users when initially powered, it would be a case of local monitoring the voltage of the supply somehow and see what fluctuation exists in order to find the source and solution.
Max.
ups is 1kva and total pc load is ~600watts

actally i have 3 lines supplying from stepdown transformer from grid
~ or > 250v
in winters its > 300v
in summers ~210

i use
1 for AConditioner
1 for pc through ups
1 in spare

industrial grade stabilizers only work here...consumer grade arent enough
that kind of voltage i get into my home..

on top of that fluctuations...its a real mess

what ever combination of lines i do same flucatuation happens

electricity dept. dosnt care

so exactly hw shud i proceed ...
any other details i shud offer so u can direct me to something in particular...
 

tcmtech

Joined Nov 4, 2013
2,867
bcoz solid state operate faster..
because of huge voltage fluctuations wen my air conditioner (external unit) starts and stops my pc shuts down..sometimes..
but most of the times..like every 2 hrs..or some..external hdds disconnect with the power fluctuations....and i can hear hdd seizures...these days...
and during that fluctuation i can hear the mechanical relay rattling
the relay doesnt rattle when i pull the plug and my pc doesnt shutdown...
Unfortunately switching out the mechanical relays for solid state won't cure the problem that you obviously have a very cheap and weak UPS and power conditioning system.

Any decent UPS will easily switch over and pick up the load seamlessly and then return it to the line power once it's stable without disturbing the computer load.

Also if computer operation is that critical and the line power issues are that bad then the most rational method to solve it would be to step up and buy a proper commercial grade UPS that comes with built in power line conditioning.
 
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