Fusion splicers are one of the most important tools available to contractors installing fiber optics today. The evolution of the fusion splicer has been dramatic to say the least. Early versions of fusion splicers were bulky, slow and some even had dials to manually align fibers. Today fusion splicers have become smaller, faster, more automated and designed for ease of use. But this evolution has not created a machine that is free of maintenance as some field technicians would believe.

Legacy Fiberoptics technicians have received factory training from major manufacturers in order to service fusion splicers down to the component level. In our experience we have found that fusion splicers are typically very well built and can withstand heavy amounts of use over long periods of time. One splicer we recently serviced had over 37,000 splices on the master counter. That machine clearly withstood the test of time.

In order to keep a fusion splicer in good working condition several steps must be taken to regularly maintain the machine. One trend that we have consistently note among the units that we service is the machines are used regularly. Most issues do not stem from lack of use, unless the machine was stored in unfavorable conditions such as extreme cold or areas of very high moisture for extended periods of time.

Maintenance of a fusion splicer starts on a day-to-day basis for a technician who uses the machine constantly. The first step that can be taken to ensure proper operation is an arc check or arc calibration.. The arc check function allows the machine to test its surroundings for temperature, elevation and humidity.   The arc check is the machine’s way of ensuring that it is set up for the best possible performance. An arc check should be performed at minimum once per day but twice per day is a better practice. A machine may require the user to perform multiple arc checks in order to optimize the arc discharge required for splicing. Choosing not to perform an arc check can create inconsistent splicing results and if not completed over long periods of time can hinder the machine’s splicing ability altogether.   Check your owner’s manual for specific instructions on performing an arc check.

A recent discussion with our lead technician identified that most machines we service do not experience complete failure of components. However those that do experience failure most commonly have issues with the cameras.   The cameras of a fusion splicer are built to create extremely high magnification and resolution capable of measuring cleave angles and fiber offsets. A core alignment fusion splicer will repeatedly align a nine micron core with such precision that most splices when testing bi-directionally with an OTDR are consistently less than 0.1dB.   Issues such as non-focusing cameras can eliminate a splicer’s ability to accurately align fibers and measure cleave properties. Why cameras fail is never a cut and dry answer as many factors can influence failure.


Splicer lens with dust build up.

Fusion splicer camera with a small amount of dust build up on the lens

Another common issue we experience with fusion splicers are electrodes. Electrodes are a Tungsten based material which directs a bolt of electricity across the fiber as a heat source to fuse or weld the fibers together. Electrodes typically need to be changed every 1,000 to 2,000 splices.  However, some manufacturers are developing ways to extend electrode life.  Electrodes should always be changed at or before the manufacturer’s recommendation. Worn electrodes not only cause the splicer to work harder to generate the electric arc but also can affect the path of the arc as well. Worn electrodes will show discoloration. There are no specific guidelines from changing electrodes based on discoloration but it is safe to assume any electrode showing black or very dark tips needs to be replaced. Arc counters on splicers eliminate the guesswork of when to change electrodes.

Over the years many debates about changing electrodes have occurred. One such debate we once encountered  was a customer saying that the electrodes should be cleaned and put back in the machine. This practice has been suggested by a couple manufacturers, however, if changes to the geometric shape of the electrode end changes, this will ultimately change the path of the arc. No matter how skilled a technician is at fusion splicing, they will be unable to observe this change in arc path. Our recommendation is to always replace electrodes, never clean. The risk is not worth the reward.


worn electrode

Worn electrodes with 2500+ arcs



If changing electrodes is a process you are not comfortable performing it is best to let a trained technician perform the service. If you decide to change your own electrodes be sure to complete the “burn in” or “electrode stabilizing” process. Failing to complete this procedure will not allow the machine to perform to the maximum potential. Also remember that electrodes should never be touched, cleaned or allowed to remain in the splicer if damaged. Something as simple as a dropped fiber holder hitting the electrodes can cause enough damage to throw off splicing functions. Replacement of electrodes is the only way to rectify the situation.


New electrodes cropped

New electrodes after the electrode stabilization process


Be sure to stop back to read our next article on Fusion Splicer Maintenance – Part Two –  Cleavers.    Where we will discuss common practices associated with cleaver maintenance for optimum splicer performance.


Have a fusion splicer which needs to be service or repair?  Contact our service team today to start the RMA process for a free evaluation.