Removable Carbon Brush Holder FAQs
- What types of generators benefit from Cutsforth’s EASYchange® carbon brush holders?
Our carbon brush holders are currently installed on gas and steam turbines, hydroelectric and at nuclear power plants. Other retrofits include chemical plants, paper mills, and oil & gas refineries. From the smallest power producers to some of the nation’s largest power companies, Cutsforth’s brush holders are quickly becoming the BEST choice for an in-service removable brush holder. In addition to the United States, Cutforth brush holders have been installed overseas in several countries.
- What brands of generators are Cutsforth’s EASYchange® carbon brush holders installed on?
General Electric, Westinghouse, Allis Chalmers, Electric Machinery, Alstom, ABB, ASEA, GM, Siemens and Hitachi.
- Why should I consider a retrofit with Cutsforth’s EASYchange® carbon brush holders?
Our brush holder will bring increased personnel safety, increased collector ring and brush rigging reliability, and decreased maintenance costs to your plant.
- What problems will Cutsforth’s EASYchange® carbon brush holders address on my generator?
Arcing, brush binding, poor terminal connections, poor spring pressure, and photographing.
Our brush holders can reduce collector ring wear and improve and protect the critical brush-to-ring connection.
- How long does a Cutsforth EASYchange® carbon brush holder retrofit take?
Entire retrofits can usually be completed in one business day. The Cutsforth team works with your company and/or outage coordinators to get our brush holders installed during your outage.
- How long has Cutsforth’s EASYchange® holders been operating in generators?
Our holders have been in service and operating over 15 years. There are currently over 30,000 Cutsforth EASYchange® brush holders in operation worldwide.
- How reliable has Cutsforth’s carbon brush holder been?
We are proud to proclaim that we have never had a failure to date from our brush holder.
- Has Cutsforth’s carbon brush holders ever been installed on DC motors?
Yes, on larger critical applications. We have our brush holders on larger DC motors such as
- Can Cutsforth’s EASYchange® carbon brush holders be installed on commutators, pilot exciters and Alterrex ring sets?
Yes, The installation variables are the brush size, ring or commutator size (width) and the existing brush rigging setup.
- How can I see a demonstration or receive more information?
We regularly schedule online demonstrations, which consist of a web-based meeting and conference call for plant personnel. Please schedule a demo by filling out this form.
Online Truing FAQs
- How do I know if my collector rings/commutator would benefit from CUTSFORTH’s Online Truing?
When you experience excessive brush vibrations (> 6 Mils), arcing, grooving, or photographing (also called imaging, ghosting or footprinting) on your ring or commutator. One or more of these issues likely makes your collector rings a good candidate for Online Truing.
- How long has CUTSFORTH been performing Online Truing?
Our company has performed our Online Truing process on hundreds of rings and commutators since 1991.
- How safe is Online Truing for collector rings and commutators?
We have safely performed truings on units around the world since 1991 and have never had a serious injury in any plant while truing.
- How much time does it take CUTSFORTH to perform the Online Truing process?
The time varies from a 2-10 hours depending on the condition of the collector rings or commutator.
- Do we need to reduce the load on our generator when the Online Truing service is in progress?
No, this is not necessary. The Online Truing process can be safely performed at full load.
- How do CUTSFORTH techs know what the run-out is when the ring is at full speed?
Our service techs measure the movement of the brush with a vibration analyzer in mils displacement. Basically, a round ring will register a low reading (generally < 2 mils) and an out of round ring will register high readings (> 6 mils is over the OEM recommended limit).
- Is the Online Truing really as accurate as other machining processes?
The process is often more accurate at creating a round surface because the work is performed on the generator while at normal operating speed and temperature. A round ring on turning gear does not always equal a round ring online.
- How do I know if my collector ring has enough life left for Online Truing?
As long is there is still a helical groove, it can be trued.
- Should I be concerned about our unit being tripped during this process?
The biggest risk of tripping a unit comes from the ground detection system. Service techs will inspect and monitor the unit for oil contamination and the collection of particles to avoid alarming the ground detection system. In rare cases, if the oil film is severe enough, they may choose to not proceed with the process until the oil leak is resolved. Cutsforth has tripped < 0.1% of the units it has performed Online Truing on over the past 20 years.
- How much lead-time does Cutsforth need to schedule Online Truing?
If you believe your unit is in an emergency state, we can usually respond within 24 hours for an expedited charge. If your unit can wait, we will work with your plant to schedule it in a timely manner.
- Who can perform this service?
All of our field service technicians are experienced and capable of performing Online Truing at your plant.
- What if I discover that the spiral groove in the collector ring is missing in places?
No problem! If tolerances allow, Cutsforth can restore the spiral groove at your next scheduled outage. Most collector rings are able to be re-grooved once in their lifetime. The minimum recommended depth of a helical groove is 0.03″.