THE ULTIMATE PACKAGED VFD SOLUTION

Mitigation of Transformer Inrush Current

Inrush Phenomenon

It is well known that energizing a transformer with rated voltage can produce a significant inrush current.  Inrush current is a random event which is not predictable and is in general not repeatable.  The magnitude of inrush current depends primarily on the following:

  1. Level of residual flux in the core of the transformer;
  2. Instant in the sine wave at which voltage is applied to the transformer;
  3. Magnitude of applied voltage.

Although the actual inrush current is a random event, it is known that the maximum peak inrush current can occur under the following conditions:

  1. Maximum positive value of residual flux in the core;
  2. Energizing the transformer at the instant the voltage is at the zero crossing in the sine wave;
  3. The applied voltage is increasing in the positive direction to add to the positive level of flux.

The following technical paper presents a method to mitigate inrush current when energizing large power transformers from a limited supply such as a generator or weak distribution system.

pdf Mitigate Transformer Current Inrush (567 KB)

Continue reading
32 Hits

SAI Drive Solutions receives Authorization to Mark the XP drive as a Listed VFD for Hazardous Locations

b2ap3_thumbnail_ETL-zoom-2.jpg

 

For Immediate Release!

Sai Drive Solutions, after two years of efforts, has been given approval by ETL to produce and mark a Listed VFD for Hazardous areas Class I Division 1 Groups B, C & D, Class II Groups E, F & G. The quest for a compliment product to the HazLo VFD began almost two years ago when development of the Frame 2 HazLo was stalled. The current HazLo offering is only economically feasible down to around 20 horsepower, so SAI began to develop a drive system that could fill the need for smaller sizes 1 – 10HP. By using a finless drive by Vacon, the engineering staff at SAI went through the design process to develop a small HP VFD suitable for classified locations that includes disconnect means and circuit protection all in one package. The result is the XP Drive for Class I Division 1 Groups B, C & D, Class II Groups E, F & G. The first phase of the certification process involved temperature testing with UL to prove the SAI design could be used as a passively cooled variable frequency drive rather than a unit that requires purged air or expensive air conditioning. After getting UL to accept the design late in 2015, the next phase of certification through ETL began. Each component of each design was closely scrutinized and evaluated per UL 1203 to make certain no aspect of the XP design was overlooked. Finally on July 7, 2016, after a lengthy inspection by the field personnel of Intertek ETL, SAI Drive Solutions was given the Authorization to Mark their XP Drive with full compliance to UL1203, Explosion-Proof and Dust-Ignition-Proof Electrical Equipment for Use in Hazardous (Classified) Locations with the file number of 5004518. For more information on this one of a kind drive solution, please visit the XP section of our web site.

Continue reading
568 Hits

Introducing the SAI Dura Drive, a pre-engineered VFD solution

SAI Drive Solutions would like to announce its launch of pre-engineered, pre-packaged VFDs!  These drive packages come in either a NEMA 1 or NEMA 3R enclosure for indoor or outdoor locations.  These drive packages include circuit breaker protection with door or flange mount disconnect means, terminal blocks for quick communication connections, a 24VDC control theme, optional drive fusing, optional output filters and available Raycap surge suppression.  The Sai Dura Drive in the NEMA 3R configuration includes a CPT, thermostat and heaters to reduce condensation.  These pre-engineered drives also feature as standard door mounted pilot lights for Control Power, Run and VFD Fault as well as door mount keypad, Hand - Off - Auto selector switch, start / stop sections, fault reset and a speed potentiometer.  One of the most unique features of these drives is the patent pending cooling method. SAI designed these drive boxes around the Vacon NXP series of Variable Frequency Drives to use existing air moving methods inherent in the drive. The result is an extremely reliable and vastly improved cooling method that eliminates the need for auxiliary air moving components which could fail and cause drive failure due to over temperature operation.  Another item to note is once each drive design was complete, prototypes were built and then tested in house in the environmental chamber on the SAI campus. Most other shops simply take the recommended air flow calculations from the VFD user manual and place air circulating fans or vents in the enclosure and then ship out the package. SAI tests each design thoroughly, in some cases to as high as 60C, to make certain the unit cools adequately.  The SAI Dura Drive is currently available in Frames 5, 6 and 7 with designs being evaluated for a Frame 8 and Frame 9. This means that these inverter drives are available today from 10 - 75 horsepower, with the FR8 and FR9 designs able to reach a whopping 200HP solution, available from stock!  Since SAI is a full UL508A panel shop, each drive is adorned with its own unique serial number and UL 508A decal to give the user peace of mind the unit will work properly from day one.  To learn more about this unique drive solution, read more under the Dura Drive section of our web site.

N3R FR5 Profile

SAI Drive Solutions would like to announce its launch of pre-engineered, pre-packaged VFDs!  These drive packages come in either a NEMA 1 or NEMA 3R enclosure for indoor or outdoor locations.  These drive packages include circuit breaker protection with door or flange mount disconnect means, terminal blocks for quick communication connections, a 24VDC control theme, optional drive fusing, optional output filters and available Raycap surge suppression.  The Sai Dura Drive in the NEMA 3R configuration includes a CPT, thermostat and heaters to reduce condensation.  These pre-engineered drives also feature as standard door mounted pilot lights for Control Power, Run and VFD Fault as well as door mount keypad, Hand - Off - Auto selector switch, start / stop sections, fault reset and a speed potentiometer.  One of the most unique features of these drives is the patent pending cooling method. SAI designed these drive boxes around the Vacon NXP series of Variable Frequency Drives to use existing air moving methods inherent in the drive. The result is an extremely reliable and vastly improved cooling method that eliminates the need for auxiliary air moving components which could fail and cause drive failure due to over temperature operation.  Another item to note is once each drive design was complete, prototypes were built and then tested in house in the environmental chamber on the SAI campus. Most other shops simply take the recommended air flow calculations from the VFD user manual and place air circulating fans or vents in the enclosure and then ship out the package. SAI tests each design thoroughly, in some cases to as high as 60C, to make certain the unit cools adequately.  The SAI Dura Drive is currently available in Frames 5, 6 and 7 with designs being evaluated for a Frame 8 and Frame 9. This means that these inverter drives are available today from 10 - 75 horsepower, with the FR8 and FR9 designs able to reach a whopping 200HP solution, available from stock!  Since SAI is a full UL508A panel shop, each drive is adorned with its own unique serial number and UL 508A decal to give the user peace of mind the unit will work properly from day one.  To learn more about this unique drive solution, read more under the Dura Drive section of our web site.

Continue reading
981 Hits

SAI Drive Solutions announces the launch of the SAI XP Drive product line of 1-10HP, Explosion Proof Drives to 55C!

SAI Drive Solutions announces the launch of the SAI XP Drive product line of 1-10HP, Explosion Proof Drives to 55C!

 

SAI Drive Solutions announces the launch of a Class I, Division 1 Explosion Proof VFD. The SAI Drives "XP" product line is a VFD for Class I, Division 1, Groups B, C & D, Class II Groups E, F & G. Sizes range from 1 - 10HP at 480V and at rated ambient temperatures of 40C, 50C or 55C, depending on customer requirements. Months of research, planning and prototype builds led up to two full days of UL witness testing of 6 configurations that would be representative samples of the 17 final variations these drives can be configured for.

 

The SAI XP drives can support horsepower ranges from 1 to 10HP, each of which can be certified for ambients of 40, 50 or even 55C. The options continue with the ability to use line or load reactors and even Raycap surge supression systems depending on customer needs. Pair these options with the input circuit breaker and handle operator with drive fuse protection and a reselient VFD design is acheived that does not rely on external forced ventlation nor costly and cumbersome air conditioners. These drives have been designed for simple field installation and use with little to no maintnance. Other drive designs rely on cooling methods that can clog or fail which could lead to costly down time, the SAI XP drive uses passive cooling to ensure a long reliable life.

 

The XP Drive by SAI Drive Solutions is a natural supplement to the patented (and UL Listed) Divsion 2 VFD, the HazLo VFD. Since SAI Drive Solutions inventories the HazLo drive as well as NEMA 1 and NEMA 3R drives, they decided to also build inventories of the XP Drive. This was no easy decision as considerable capital investment was required not only by SAI management but with their distributor partners as well. However, with careful planning and an extended investment of inventory, SAI Drives can offer lead times as short as ONE DAY for the XP Drives. This lead time was recognized by one lucky custmer in December of 2015 when they placed an order for what originally had been a 30+ day lead time, as they were informed the unit was actually in inventory and could ship to them as soon as needed! Thus the first stocking unit of the XP drive did not last long, but thanks to the efforts of the SAI team, the next stock unit was be available on the next business day and efforts continue to build up stock of what will be the next fast selling, need fulfilling SAI Drive Solution.

Continue reading
1393 Hits

HazLo Drive now available in 575V and/or Stainless Steel

HazLo Drive now available in 575V and/or Stainless Steel

SAI Drive Solutions and Vacon are pleased to announce, two long awaited versions of our HazLo Drives, a 575V option and a Stainless Steel enclosure option! Choose one or both new versions.  Yes, the HazLo is now available as a stainless steel variable frequency drive , it's complete chassis is manufactured from 316SS.

Further, we are continuing develpment of the HazLo product line for Class II and Class III areas. This enclosure rating will then allow our uniqe Division 2 drive to be located not only in locations where gasses could occur but also in environments with flammable dust or fibers, thus permitting a much wider application range for this One of a Kind VFD.

Contact us now for more information on these (or any other) configurations, we can package drives from NEMA 1 to NEMA 7 Explosion Proof.

Continue reading
2050 Hits

SAI's Second shipment of stock drives arrives

SAI Drive Solutions recently took delivery of our second large order of drives for stock.

Continue reading
1743 Hits

Houston, we have a functional environmental chamber!

Houston, we have a functional environmental chamber!

 

It seems as if construction only just began on the 10' x 10' environmental temperature controlled test chamber at SAI Drive Solutions. Yet, the project has already been completed and is in the final stages of PID fine tuning.

Continue reading
2887 Hits

SAI Drive Solutions begins construction of Environmental Chamber

SAI Drive Solutions begins construction of Environmental Chamber

SAI Drive Solutions begins construction of a 10' x 10' "Environmental Chamber" for heat rise testing of variable frequency drives (and other equipment when requested or contracted) to over 50 degree C. The concept of this chamber is simply to take an ISO Shipping container, convert and automate a system for heat rise tests.

Continue reading
2627 Hits

SAI Offers VFD Rental fleet to 1500HP, 480VAC

SAI Offers VFD Rental fleet to 1500HP, 480VAC

 SAI Drive Solutions now offers VFD Rentals from 15 - 1500HP. These drives are 460V, all of them are portable via hand truck or forklift. They are framed out with square tube steel for durability that rental equipment demands. Larger units include a means of disconnect and HVAC if required. Weekly and Monthly rates are available for these stand by / back up Variable Frequency Drives. Use these rental drives to help minimize your P.M. downtime!

Continue reading
2185 Hits

SAI Drive Solutions receives first VFD stock order 1 - 600HP VAC

SAI Drive Solutions receives first VFD stock order 1 - 600HP VAC

SAI recently took receipt of it's first order of Vacon variable frequency drives from the NXP family. SAI wanted a robust, heavy duty rated drive that would fit the majority of applications from around the gulf coast. In that, they chose the NXP line from Vacon in wall mount and stand alone units, both designs are NEMA 1 an IP21 rated. These drives range from 2.2a up to a massive 730a, 480VAC, 60hZ. The NXP series was a natural inverter choice for SAI as it is rated for 50C, (frames 4 - 10) and comes with conformally coated circuit boards (aka varnished). This conformal coating helps protect the critical electronic components from moisture and dust particulates. These three key factors (higher than standard ambient, Heavy Duty rating and varnished boards) of a VSD is what led SAI to choose the NXP line up. SAI Drive Solutions can find solution for your drive need or Solutions would not be part of the name!

Continue reading
1701 Hits

SAI hires 3 panel wiremen to keep up with demand

SAI hires 3 panel wiremen to keep up with demand

SAI recently hired three experienced panel wiremen due to increased demand for SAI products.  The new, full-time employees were hired to compliment the existing workforce.   The continued rise in demand for product has been driven by an increased requirement for legacy products as well as a response to our new HazLo and Dura-Drive series pump controllers. For more information on SAI Drives:

PHONE: 281.516.3130
Info@saidrives.com
11311 Holderrieth Building 200
Tomball, TX 77375

Continue reading
1344 Hits

SAI Drives Launches Our New Website

SAI Drives is proud to announce the launch of our new company website at www.saidrives.com . Our new site is a great resource for clients to learn more about our exciting line of products and services as well as stay informed about company events. We will be continuously updating our website with technical documents and case studies as well as company news. Please make sure to fill out our contact form to let us know you were here.

Continue reading
1304 Hits

SAI Drives Announces the all new HazLo VFD at PCIC Show

SAI Drives Announces the all new HazLo VFD at PCIC Show

SAI Drives Announces the all new HazLo VFD at P.C.I.C. Show in Chicago. This year's PCIC was held Sept 23-25th 2013 at the Marriott Magnificent mile in Chicago. Hundreds of visitors came through the SAI Drives booth and saw first hand how the HazLo drive is a game changer in our industry. To learn more about the HazLo drive visit our website at www.saidrives.com or contact our sales department at 281.516.3130.

Continue reading
1394 Hits