FranklinTECH goes on the road: Southeastern US

Throughout the year, Franklin holds all-day training seminars at our three FranklinTECH campuses and other selected locations across the country. These seminars focus on water system basics, the proper application of Franklin Electric submersible products, and troubleshooting. As always, these are provided at no cost to you, and lunch is even included.

As part of this training commitment, Franklin Electric is pleased to announce the following dates and locations for upcoming all-day seminars in the Southeast Region:

These seminars count toward Certified Contractor status for the 2013 Key Dealer program, and in most cases, qualify for Continuing Education credit as well.

You can also take advantage of the next session at our training center in Wilburton, Oklahoma on September 11- 12.

To register for a session, contact our Hotline at 800.348.2420 or hotline@fele.com. Space is limited and registrations are handled on a first come, first served basis, so get your spot reserved as soon as possible. We hope to see you soon at a FranklinTECH seminar this fall!

Column-by-Column: Locked Rotor Amps and KVA

In our column-by-column review of single-phase motor specifications, we are finally at the last two columns on page 13 of the Franklin Electric AIM Manual. These two columns are Locked Rotor Amps and KVA Code.

Locked Rotor Amps, sometimes abbreviated LRA, is exactly what the name implies. If the rotor is locked and can’t move while electrical power is applied, the motor will draw this many amps. Locked Rotor Amps are much higher than running amps, generally around five times max running amps. For example, maximum load for a 1.5 hp, 2-wire motor are 13.1 amps. Locked Rotor Amps for this same motor are 66.2 amps.

An example of when the motor draws Locked Rotor Amps is in the case of a bound pump. In this scenario, the motor’s overloads will trip and take the motor offline in a few seconds to protect the motor.

However, another, much more common instance where the motor draws Locked Rotor Amps is at start up. That is, every time a motor is started, it pulls Locked Rotor Amps for a split second. The reason is that at the moment electrical power is applied, the rotor hasn’t started to rotate yet. So, for that instant, the motor thinks the rotor is locked. Once the motor starts to turn, amperage falls to something between full load and maximum amps. Once again, this happens very quickly, in a few tenths of a second.

Knowing the value of Locked Rotor Amps can be important in some installations, especially in terms making sure we’ve got the appropriate electrical service. For example, many older homes still have 50 amp service. So a 4-inch, 2-wire, 115 volt, ½ hp motor that pulls 64.4 amps at start up could potentially fail to start. There simply isn’t enough electrical current available to get the motor started. The equivalent 230 V motor in this case would be a much better option.

Locked Rotor Amps is also an important aspect of sizing reduced voltage starters (RVS). Reduced voltage starting is one type of soft starting, and these devices “ramp up” the voltage versus applying the full voltage all at once. This greatly reduces the Locked Rotor Amps at start-up.

Reduced voltage starters are rarely used with the single-phase motors listed here. However, if they were, this is where KVA Code comes in, and is used to specify the size of reduced voltage starters. Since reduced voltage starters are much more common and important with higher horsepower, 3-phase motors, we’ll save explaining where the KVA Code comes from when we discuss 3-phase motor specifications.

That wraps up the eighteen columns on page 13 of the AIM Manual. Next week, we’ll jump over to page 14 and start covering fuse and circuit breaker sizing.

For more help in the field concerning troubleshooting and installation, call our Technical Service Hotline at 800.348.2420 or email at hotline@fele.com.

Column-by-Column: Motor Model and Rating

We previously established the wealth of knowledge held in the AIM Manual for contractors and installers and the two pages that stand out (pages 13 and 14). Packed with information essential to single-phase motor installation and troubleshooting, we continue in this post to review pages 13 and 14 column-by-column.

Again, if you are dealing with 50 Hz motors, you will need a 50 Hz AIM Manual. Also, for those dealing with a 3-phase motor, please reference the table on page 22 of the AIM Manual. This series will focus on Franklin single-phase submersible motors.

Continuing from our last post, working across table 13 on page 13 of the AIM Manual, the second column is labeled the motor model prefix or motor model number. Franklin Electric submersible motors have 10 digit model numbers, this column contains the first 6 of those. Each of these numbers means something, but it’s not important to know what they mean. After all, that’s why the motor rating, voltage, and hertz are etched on the nameplate. Continue reading