How to purchase a VFD?
Basically, it depends on brand and power and how old has the VFD due to the component type, meaning for example that due to the fact that now cabinet drive are very compact the component warm is higher than for a drive of 15 years before.
Then if you buy low cost brand for pump and fan for power below I would say around 100 kW most of the time you reach the ROI take about in 1 or 2 years so you can easily buy another 3 or years after, you already have win money during last 2 years of using old one.
So for easy and small drive power application, better to buy a new one and why not try a new VFD brand to see if it easiest to use and tune...look to very huge application, ex Alstom, now Converteam has very huge drive running since more than 10 or 15 years without any trouble just some maintenance like some diode or fan or filter or things like that.
Your knowledge base should at least be considered when purchasing. So many customers are plagued with the salesman that promises long life, inexpensive primary investment and how quick you can get it. In most cases if there is an application or programming issue and that same salesman will be hard to reach or he will give you the 1-800 number to tech support and you will be stuck with trying to explain your issue to someone who either has limited field experience or is digging through a manual while on the phone. He is selling a box and should be avoided. Local, trained field personnel from whom you buy your product should be primary when considering brand and you should consider the knowledge base of your customer as well. Are they going to properly maintain? Are they trained on the product and is who you are buying from willing to train your customer?
Let's face it, variable frequency drives are becoming commodities in the market and usually driven by price rather than any other factor until they get onsite and either don't fit the application or the customer is disturbed because they can't get assistance.
MTBF ratings are arbitrary as they do not take environment into consideration. A VFD in a clean room with a moderate ambient will usually outlast and outperform a VFD in a plant environment that has high ambients with a large particulate issue. Generally, manufacturers produce a 10-15 year MTBF rating but, board level capacitors are only rated at 5 years by their manufacturers. Fans have a much lower rating and would be adjusted due to environment.
My suggestion when considering manufacturers of VFD drives, purchase from a local authorized service provider for that manufacturer and stay away from anyone who doesn't have a certified VFD specialist on staff.
Then if you buy low cost brand for pump and fan for power below I would say around 100 kW most of the time you reach the ROI take about in 1 or 2 years so you can easily buy another 3 or years after, you already have win money during last 2 years of using old one.
So for easy and small drive power application, better to buy a new one and why not try a new VFD brand to see if it easiest to use and tune...look to very huge application, ex Alstom, now Converteam has very huge drive running since more than 10 or 15 years without any trouble just some maintenance like some diode or fan or filter or things like that.
Your knowledge base should at least be considered when purchasing. So many customers are plagued with the salesman that promises long life, inexpensive primary investment and how quick you can get it. In most cases if there is an application or programming issue and that same salesman will be hard to reach or he will give you the 1-800 number to tech support and you will be stuck with trying to explain your issue to someone who either has limited field experience or is digging through a manual while on the phone. He is selling a box and should be avoided. Local, trained field personnel from whom you buy your product should be primary when considering brand and you should consider the knowledge base of your customer as well. Are they going to properly maintain? Are they trained on the product and is who you are buying from willing to train your customer?
Let's face it, variable frequency drives are becoming commodities in the market and usually driven by price rather than any other factor until they get onsite and either don't fit the application or the customer is disturbed because they can't get assistance.
MTBF ratings are arbitrary as they do not take environment into consideration. A VFD in a clean room with a moderate ambient will usually outlast and outperform a VFD in a plant environment that has high ambients with a large particulate issue. Generally, manufacturers produce a 10-15 year MTBF rating but, board level capacitors are only rated at 5 years by their manufacturers. Fans have a much lower rating and would be adjusted due to environment.
My suggestion when considering manufacturers of VFD drives, purchase from a local authorized service provider for that manufacturer and stay away from anyone who doesn't have a certified VFD specialist on staff.
