Technical Tips
Motor Controllers & Self-protected Combination starters
May 2022
Method of Marking/Tagging the KT_9 Motor Controllers
Are there any snap-in marker cards or adhesive label options to tag the KT_9 products?
May 2022
KT_9 Handle Stops At Or Below Trip Position When Breaker Is Turned Off
Why does my motor controller handle not turn completely to the off position?
November 2018
Using KT_7-25S/25H/45H Controllers on Non-Motor/Resistive Loads
Can a KT_7-25S/25H/45H controller be used a branch circuit protection on non-motor or resistive loads like a heater?
November 2015
KT7 Front Mount Vs. Side Mount Auxiliaries
What is the maximum voltage rating of KT7 front mounted auxiliary contacts verses side mounted auxiliaries. How do these differences effect KT7 assembled devices, such as E-Combo starters?
May 2015
Use of KT7 Motor Controllers with variable frequency drives
A motor branch circuit including a variable frequency drive and one or more KT7 Motor Controllers is a complex system. Successful performance depends on all components, devices and their interconnections. Several key points must be considered when using KT7 devices with VFDs.
Whitepaper
May 2015
What is the replacement for KTA3-100 Motor Controllers?
I have a KTA3 in my multi-motor control panel. What is the replacement? What are the alternatives to KTA3 Motor Controllers? KTA3-25 controllers transitioned to KT4 or KT7 controllers. KTA3-100 controllers were replaced with KT7 controllers, but only up to 45 amps.
April 2015
What are KF7 Fuse Holders used for?
KF7 fuse holders can be applied on the line side of KTA7 or KTC7 motor circuit controllers and matching CA7 contactors. KF7 can also be connected on the line side of a CA7 contactor and/or starter as you would a standard fuse holder. This can increase a panels KAIC rating.
March 2015
KTU7 Molded Case Circuit Breaker Busbar Alternatives
KTU7 busbar can be used on both KTU7 and KT7 motor controllers, but KT7 busbars cannot be used on KTU7 MCCBs. What are some alternatives when assembling multi-motor starter panels?
November 2014
How to specify a disconnect, short-circuit & overload device in one unit
Proper selection of motor controllers for self-protection relies on the motor FLA, and the motor HP. Choosing based solely on motor FLA can cause problems.
June 2014
Short Circuit Current Ratings (SCCR) and Control Circuits
Do the components in a control circuit have a short circuit current rating? UL and NEC rulses define which components in a control panel require a short circuit current rating.
December 2013
Converting KTA3-25 to KT4 Motor Controllers
My panel uses a KTA3-25 motor controller. What is the replacement for this device? KT4 Manual Motor Controllers are a direct replacement for KTA3-25 controllers with only a few exceptions.
November 2013
How to choose the right KT7 busbar power wiring system
There are several different types of bus bar systems available. How do I know which system to choose for my assembly? If I have an old bus bar system, what is the current replacement recommendation? What if I need to add a unit to an existing system?
August 2013
Installing KT7 Handles in an Extra Deep Enclosure
When I mount KT7 in a deep enclosure the shaft seems to droop and miss the handle mechanism. What do I do?
March 2013
Can components be reused after a short-circuit?
Unlike the fuse box in most residential power centers, industrial circuit protection can rarely be reused after a short-circuit. Some products are specifically tested by UL to withstand a short circuit.
May 2012
The big motor and a little motor rule
A little known rule of UL inspectors outlines what protection should be used in multi-motor starter panel applications.
August 2012
How to specify motor circuit breakers
A variety of products can be used to perform as a circuit breaker for motor and non-motor loads, but some perform better than others.
December 2012
Door Interlock Mechanisms on CX7 KWIKstarters
CX7 KWIKstarters are UL508 approved because they have a removable cover instead of a hinged door. Rules specifically outline the difference between a cover and a door.
September 2012
Using bus bars in multi-motor starter panels
When mounting multiple motor controls in a multi-motor panel, using bus bars is an efficient use of space. Installing the right bus bar for the job can make a big job simple.
September 2012
Wye power vs. Delta power systems
What is the meaning of a delta connected system versus wye connected power systems when applied to motor controllers and circuit breakers?
May 2008
The importance of Primary Fuses in enclosed circuit controllers
Most panels without control transformers are ordered without any “optional” control circuit fuse, which can leave the control circuit wiring unprotected.
Whitepaper
March 2012
Methods of Applying KT7 Motor Controllers
Proper design and compliance with UL/CSA and NEC standards for motor controllers and circuit breaker devices.
Whitepaper