Install Capacitor Into Laser printer so it stops tripping the circuit breaker

Thread Starter

Luigi5000

Joined Jan 21, 2017
4
I have a Brother L2360DW Laser printer. It commonly trips the circuit breaker when I print something. Laser printers require a spike of electricity when they first begin to print.

Apparently Brother sometimes doesn’t put large enough capacitors inside their printers to accommodate the required electrical spike and not end up spiking the house-wiring.

Does anyone know, does my printer have a DC converter just inside? If so, could I simply get a large capacitor of the appropriate voltage, and solder it onto the outputs of the DC converter to keep the printer from tripping the circuit breaker?
 

MrChips

Joined Oct 2, 2009
24,238
I think you're barking up the wrong tree.

What is the current and power rating of your printer?
What is the current limit on your breaker?
What other loads are on the same breaker?
 

crutschow

Joined Mar 14, 2008
27,762
The large current spike is likely due to the fuser heater in the printer which takes several seconds to heat up, so I don't think a capacitor will help that.
I've noticed that my lights actually dim slightly when that heater kicks in.

You can try putting the printer on a different circuit if one is available, if you already have the computer and/or other significant power drain on that outlet.
Otherwise you may need to check the breaker to see if it can be replaced with one that has a slow-blow or high-inrush delay characteristic.
You don't want to replace it with a higher current breaker since that would be against code and be a safety hazard.
 

tcmtech

Joined Nov 4, 2013
2,867
Sounds like either a weak breaker or an already overloaded one that needs some of the load transferred to a different circuit.

Neither is a printer issue in my views.
 

spinnaker

Joined Oct 29, 2009
7,835
I have a Brother L2360DW Laser printer. It commonly trips the circuit breaker when I print something. Laser printers require a spike of electricity when they first begin to print.

Apparently Brother sometimes doesn’t put large enough capacitors inside their printers to accommodate the required electrical spike and not end up spiking the house-wiring.

Does anyone know, does my printer have a DC converter just inside? If so, could I simply get a large capacitor of the appropriate voltage, and solder it onto the outputs of the DC converter to keep the printer from tripping the circuit breaker?

Get a different printer and / or call in a qualified electrician. Don't try to modify the printer then take the chance of burning down your house. Mind you you want to modify it with what you have learned over the internet. :confused: The breaker is tripping for a reason. Either the breaker is bad or the printer is bad. Maybe it is a poor design? Still not worth burning your house down in an attempt to fix it.
 

SeymorG

Joined Jan 25, 2021
2
As an IT consultant, I’ve encountered this problem many times. The AFCI breaker detects an arc inside the laser printer when it prints. The arc is legit. Vacuum cleaner motors also make legit arcs that trip AFCI breakers. AFCI is too dumb to distinguish between the legit arcs in some devices and dangerous arcs in walls.

It’s maddening. Some clients switch to a non-AFCI breaker against code to be able to print. I certainly don’t authorize or perform that but some clients’ electricians do it.

The AFCI breaker has a primitive “smart” (oxymoron) component that looks for the frequency characteristics (I think around 100KHz lasting for a few milliseconds) of an arc in order to prevent fires resulting from arcing wires in walls. Either the normal legit arc in some laser printers has a frequency indistinguishable from an arcing wire in a wall or the simple circuit in the AFCI has too broad a frequency range and duration to ignore the different frequency of the legit arc in the laser printer.

Either way, there are only 4 options I know:

- replace the AFCI breaker with a regular breaker but violate code and increase danger by not being protected from arcs in wall wiring and extension cords

- use an inkjet printer

- find through trial and error a laser printer that doesn’t trip the AFCI breaker

- isolate the laser printer with an “isolation transformer,” e.g., a box you plug into the wall then the printer into the box; companies like tripp lite sell many models, but make sure you get one rated with wattage that can handle the peak wattage of your laser printer, which can be very high (1,000w ??); also, cooling fans in some isolation transformers are be loud so note the decibel rating; I considered using isolation transformers but haven’t yet.

As far as I know, only an isolation transformer can hide the legit arc power frequency inside a device from a circuit breaker, which only sees the isolation transformer’s.

In the future, I hope laser printer manufacturers account for AFCI breakers in their printer design and/or AFCI breakers improve with more sophisticated chips that distinguish between legit arcs in consumer products and dangerous unintended arcs in walls and extension cords.
 

Tesla23

Joined May 10, 2009
483
The AFCI breaker has a primitive “smart” (oxymoron) component that looks for the frequency characteristics (I think around 100KHz lasting for a few milliseconds) of an arc in order to prevent fires resulting from arcing wires in walls. Either the normal legit arc in some laser printers has a frequency indistinguishable from an arcing wire in a wall or the simple circuit in the AFCI has too broad a frequency range and duration to ignore the different frequency of the legit arc in the laser printer.
I have no direct experience with this, but if the issue is the 100kHz ripple, the easiest (and safest) thing to try maybe to use an existing filter, e.g. something like:
http://www.farnell.com/datasheets/3098163.pdf
I would guess your issue is a differential mode signal, and the simple EMI filters typically don't have much effect below 1MHz.

Maybe you should try the best filtered power board you can get your hands on first.

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BobaMosfet

Joined Jul 1, 2009
1,854
I have a Brother L2360DW Laser printer. It commonly trips the circuit breaker when I print something. Laser printers require a spike of electricity when they first begin to print.

Apparently Brother sometimes doesn’t put large enough capacitors inside their printers to accommodate the required electrical spike and not end up spiking the house-wiring.

Does anyone know, does my printer have a DC converter just inside? If so, could I simply get a large capacitor of the appropriate voltage, and solder it onto the outputs of the DC converter to keep the printer from tripping the circuit breaker?
This is a known design flaw with many Brother printers. You might fix it with a thermistor, to limit the inrush current so the GFI isn't thrown.

OEM: Ametherm, Inc.
Components: SL12 10006, MS32 50006 (One of these might work for you).
 
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