Category
- Products
-
- FAQ
- Contact us
AC Drive Manufacturer
AC Drives Offer Benefits Beyond Energy Savings
AC drives have a well-deserved reputation for energy savings. But it's important to analyze AC drive various applications carefully to ensure that the system will has expected savings. The nature of the AC drives systems are applied to will determine the extent of possible savings.
AC drives have proven their value in a wide variety of applications where energy can be saved by reducing the speed of a ac motor. With variable-torque centrifugal pump or fan applications, reducing the motor speed saves more energy than you might expect, since energy use decreases by a cube function in relation to the reduction in motor speed.
The benefit of an AC drive goes beyond energy savings. The best thing about an AC drive is that it offers a way to enable the system to best meet the application. Varying the flow of something is usually a very precise way of meeting the load. An AC drive is a tool to make the system run better.
Most comfort cooling or water pumping applications are designed for the worst case, which means that they're oversized for conditions that exist most of the time. The AC drive enables the system to match the load.
When it comes to existing buildings, however, things can be more complicated. To ensure that the AC drive will be effective, it's important to take a close look at the equipment that's already installed. You need a way to slow the motor down. If you don't slow the motor down, you don't get savings. Existing systems that apply constant speed motors with mechanical restrictions to deliver variable flow are prime candidates for energy savings with AC drive. Systems that require constant flow, however, will typically require more expensive mechanical rework in order to capture AC drive savings.
For example, if a constant volume pump is delivering water to heating coils that have three-way valves on them, it won't be possible to reduce the pump speed without making other changes to the system.
A lot of existing pump and fan systems have some way to reduce the flow. If your system already has some mechanical means of limiting flow by increasing pressure drop, that's a great candidate for an AC drive. In this case, the mechanical means — such as dampers, vanes, or valves — should be removed during AC drive installation.
What's more, if the mechanical restriction was automatically controlled, you may already have the sensor you need for the AC drive. In other words, it might be possible to reuse an existing differential pressure sensor to control the new AC drive speed, instead of the old dampers, vanes, or valves.
But the potential for energy savings will vary from one system to the next. For example, the savings from replacing vortex vanes with an AC drive aren't as dramatic as the savings from replacing an old constant volume fan that had an isolation damper to reduce flow.
There are many opportunities for the use of AC drives in various applications. The savings are very compelling. In most cases there is something you can do, but you have to be a little clever when you're looking at retrofits. It's not as simple as slapping an AC drive on instead of a starter and assuming that energy use will drop.
It's worthwhile to remember that AC drives can offer benefits beyond energy savings, such as a soft start and the ability to ramp up and down, which might prolong the life of equipment or eliminate water hammer problems.
Another potential advantage is information. There's a lot of good diagnostic data that you can get out of the variable frequency drive. With that data, facility managers can extract an estimate of power consumed to do some basic measurement and verification.
If the facility is running fault detection and diagnostics, that software can keep an eye on system performance. If you have an AC drive, you can start writing rules comparing power to speed, to delivered volume and start looking for anomalies automatically.
It's is easier and less expensive than in the past to connect an AC drive to a building automation system. While serial or Ethernet data connection ports used to be sold as an optional upgrade, today everybody just gives you the port, along with a choice of protocols.
Facility managers considering AC drive applications should check to see if there are incentives available for the project. AC drive incentives are common right now. But it's important to be aware of the rules associated with the incentive program.
AC drives have proven their value in a wide variety of applications where energy can be saved by reducing the speed of a ac motor. With variable-torque centrifugal pump or fan applications, reducing the motor speed saves more energy than you might expect, since energy use decreases by a cube function in relation to the reduction in motor speed.
The benefit of an AC drive goes beyond energy savings. The best thing about an AC drive is that it offers a way to enable the system to best meet the application. Varying the flow of something is usually a very precise way of meeting the load. An AC drive is a tool to make the system run better.
Most comfort cooling or water pumping applications are designed for the worst case, which means that they're oversized for conditions that exist most of the time. The AC drive enables the system to match the load.
When it comes to existing buildings, however, things can be more complicated. To ensure that the AC drive will be effective, it's important to take a close look at the equipment that's already installed. You need a way to slow the motor down. If you don't slow the motor down, you don't get savings. Existing systems that apply constant speed motors with mechanical restrictions to deliver variable flow are prime candidates for energy savings with AC drive. Systems that require constant flow, however, will typically require more expensive mechanical rework in order to capture AC drive savings.
For example, if a constant volume pump is delivering water to heating coils that have three-way valves on them, it won't be possible to reduce the pump speed without making other changes to the system.
A lot of existing pump and fan systems have some way to reduce the flow. If your system already has some mechanical means of limiting flow by increasing pressure drop, that's a great candidate for an AC drive. In this case, the mechanical means — such as dampers, vanes, or valves — should be removed during AC drive installation.
What's more, if the mechanical restriction was automatically controlled, you may already have the sensor you need for the AC drive. In other words, it might be possible to reuse an existing differential pressure sensor to control the new AC drive speed, instead of the old dampers, vanes, or valves.
But the potential for energy savings will vary from one system to the next. For example, the savings from replacing vortex vanes with an AC drive aren't as dramatic as the savings from replacing an old constant volume fan that had an isolation damper to reduce flow.
There are many opportunities for the use of AC drives in various applications. The savings are very compelling. In most cases there is something you can do, but you have to be a little clever when you're looking at retrofits. It's not as simple as slapping an AC drive on instead of a starter and assuming that energy use will drop.
It's worthwhile to remember that AC drives can offer benefits beyond energy savings, such as a soft start and the ability to ramp up and down, which might prolong the life of equipment or eliminate water hammer problems.
Another potential advantage is information. There's a lot of good diagnostic data that you can get out of the variable frequency drive. With that data, facility managers can extract an estimate of power consumed to do some basic measurement and verification.
If the facility is running fault detection and diagnostics, that software can keep an eye on system performance. If you have an AC drive, you can start writing rules comparing power to speed, to delivered volume and start looking for anomalies automatically.
It's is easier and less expensive than in the past to connect an AC drive to a building automation system. While serial or Ethernet data connection ports used to be sold as an optional upgrade, today everybody just gives you the port, along with a choice of protocols.
Facility managers considering AC drive applications should check to see if there are incentives available for the project. AC drive incentives are common right now. But it's important to be aware of the rules associated with the incentive program.
Post a Comment:
You may also like:
