this motor of oil pump one of them is main and the other is auxiliary,working only when the oil pressure is decrease.Irating=4.98amp,volt=400volt,Istarting=27.5amp
It might not be for USA.Hevy,
You need to supply more info.
Why 400V? Why not 460 or 480?
I agree with that. For the type of UPS we often use, a 150% overload capability is typical which would thus give a continuous rating of just over 15kVA assuming the starts can be staggered.Still leaves some question as to whether both can start concurrently...???
Anyway you look at it, your going to need at least a UPS in the 22.5kVA instantaneous range: 400V ? (27.5A + 5A) ? √3.
Keep in mind this is the minimum if both motors will not start concurrently. The continuous rating can be lower, but likely not as low as 2 ? 5A would seem to indicate. In general, the continuous rating is about 60 to 80% of the instantaneous.
There are two different factors. The run-time, or autonomy as it is often called, is dependent on battery capacity. The inverter output rating isn't. For example, a 15kVA unit with 3 hour autonomy couldn't supply a 45kVA load for one hour.Take this info with a grain of salt. I am far from being adept in UPS ratings and considerationsAs such, I have a question. Would not the rating be in kVA-hrs? After all, you'd need to know how long the UPS could maintain the loads when normal service is interrupted.
There are two different factors. The run-time, or autonomy as it is often called, is dependent on battery capacity. The inverter output rating isn't. For example, a 15kVA unit with 3 hour autonomy couldn't supply a 45kVA load for one hour.
could any one help me to know how many kva i need in ups to supply two motors both of them have same specification (2.2kw,4.98amp,I starting 28amp)thx for corp.
Never put motors on UPS. Install a generator. The there will be a 10 sec. maximum delay. Have the generator supplier size the genny.
Never put motors on UPS. Install a generator. The there will be a 10 sec. maximum delay. Have the generator supplier size the genny.
Never put motors on UPS. Install a generator.
Why shouldnt motors be on UPS?
1. The UPS is designed for rated kW and kVA. Provided the load remains within those constraints it isn?t a problem.Perhaps I should've been more elaborate and stated: properly investigated applications should seldom, if ever, would require the installation of an UPS to support a motor drive.
Having said that on my very first job - eons ago it seems - I did put two motors on a UPS system. It was warranted. Not since.
Several reasons:
- UPS's are not designed for the load profile that a motor would represent.
- as per the above the engineers at UPS manufacturers are not really equipped to properly determine the size of an optimum UPS for a motor load.
- The UPS would need to be oversized and the cost of the batteries would also rise exponentially.
- Seldom are there is a motor application that could not sustain a short - 3-4 second - outage until the generator comes up.
- Should UPS be used, how long will it be needed? All that time is to be supported by batteries that are:
- Expensive,
- Highest cause of UPS unavailability so often times battery monitoring and dual battery bank is warranted for high MTBF that again will make the cost skyrocket.
- What happens after the batteries exhausted? Would you have a generator anyway?
- If all the above are not taken into consideration a UPS may be installed, but the U may be replaced by an I as in Interruptible.
1. The UPS is designed for rated kW and kVA. Provided the load remains within those constraints it isn?t a problem.
2. Agreed. That?s why you and I get paid the big bucks to ensure that the kit is suitable for the application.
3. Yes, and that?s how the 15kVA rating was arrived at. Battery capacity is a matter of autonomy.
4. Starting up a 1500kVA Diesel genny for a pumping station or a hospital might take just a tad longer.
5. Sure, batteries are expensive. So are standby generators.
6. See 5.
7. We provide UPS systems for many public buildings, hospitals, servers etc. Typical autonomy required is three hours. That is routinely tested on a twice yearly basis. For critical back-up, nothing less would be acceptable.
8. Depends on application. For something like a cinema you would expect evacuation of the building within the three-hour autonomy. For servers you would reasonably expect an orderly shut down. For hospitals you would certainly have back up Diesel generators.
9. Modern UPS systems have pretty good monitoring and comms facilities. That?s not to say you can?t get failures. You just might get an indication of it before it might be required to perform in anger. And there is no certainty that a rotary alternator driven by a reciprocating combustion engine will be 100% reliable 100% of the time.
UPS's are not designed for motor inrush characteristics.
Disagree - UPSs are not the most reliable devices known to man, and a pair of UPS (each with own battery) followed by a static switch is always a worthwhile increase in reliability, if the budget is there. Even better is dual distribution systems and have all loads dual supplied; this allows maintenance work on one of the two UPS / distribution chains whilst the other chain keeps everything up and still has UPS and genset protection.A properly designed system for optimum reliabilty is a UPS with dual battery banks equipped with individual cell monitoring for about 5 minutes duration and a life-safety grade gen'set that feeds the UPS via a transfer switch. Overall it has higher reliability as a redundant UPS with gen'set backup.
Disagree - UPSs are not the most reliable devices known to man, and a pair of UPS (each with own battery) followed by a static switch is always a worthwhile increase in reliability, if the budget is there. Even better is dual distribution systems and have all loads dual supplied; this allows maintenance work on one of the two UPS / distribution chains whilst the other chain keeps everything up and still has UPS and genset protection.