Why Siemens Tandem Breaker

Why Siemens Tandem Breaker Won’t Fit? [Top 3 Reasons]


Found faulty Siemens tandem breakers after realizing the circuits related to the common neutrals? Or maybe, you couldn’t detect the issue of not getting fit in the panel, right?

Well, we got your problem! We have prepared the reasons behind facing issues between the breakers and the panel in this article.

So, Why won’t Siemens tandem breaker fit the panel?

Well, allowing common neutral installation comes with overloading issues. Also, having an arc-fault circuit interrupter(AFCI) and ground-fault circuit interrupter(GFCI) might interrupt fitting between them. Along with that, flat bus bars do not permit fitting the tandem breakers in position.

That’s not all for sure! We have several things to explain to you in detail.

Till then, engage with us!

Top Reasons Behind Siemens Tandem Breaker Won’t Fit

Below are some of the common reasons and their solutions to why a siemens tandem breaker won’t fit. Let’s see them-

Reason 1: Allowing Common Neutral

A common problem with tandem breakers relates to the wrong process of the installation. You might know that this breaker allows installation on a single phase. 

Meanwhile, the usage of a common neutral can be dangerous after sharing with the circuit. Just like a thousand other tandem breakers, Siemens also has this restriction. 

In the long run, you might see the neutral wire going overloaded or worn out. Also, the bus bar can also get damaged. 

So, utilizing only one space in the breaker box is standard. Along with that, you will find it connected to the hot bus bars. So, it limits the capability to employ a single three-wire cable to provide for both circuits.

On the other hand, configurations such as kitchen countertop circuits, where two hot wires are existing. 

In the meantime, these can feed separate circuits sharing a common neutral wire. That means the hot wires must be attached to different hot bus bars. 

But this is unimaginable on the tandem breakers. So, without having individual cables feeding both circuits, you can’t execute this breaker. That’s why checking this while inspecting tandem breakers is a must!


Basically, neutrals do not have any breakers. Meanwhile, it can not carry more specific heat. However, there is a unique natural solution existing. 

What if you find no cross-hot leakage in the neutrals? It indicates no overloading taking place due to the neutrals. However, you can not rely on this uncertain event at the same time. 

To get the neutrals doable, we can give you some tips indeed. 

First of all, taking any two circuits is required. In the meantime, these should belong to the different poles. 

Let’s imagine a 2-pole is connected with these two circuits containing different amperes. Along with that, let’s assume one is a red indicator while the other is black. 

While you have the red hot drawing at some ampere amount, it draws from the black. If one is 15A and the other is 13A, clearly you see the difference goes 2A. 

Similarly, neutral also carries the differences in currents. Now, you see the neutral is always lesser than the bigger current flows, right? Meanwhile, this configuration is safer and protected for the neutral. 

However, there are some prerequisites to handle. The breaker should come as a 2-pole containing 240 volts. Along with that, breaker handles must get shut off altogether. 

There is a handle tie available in the market. Moreover, this is authorized by the manufacturing factory. 

Actually, we just started the fixing from now on. Check or measure between those two shared hot wires. 

If you find 240 volts, then everything is alright. Unless reading such as null volt might end up overloading the neutral.

However, meeting the rules with the handle ties can be an option. But expensive nature might keep your interest lower. 

Along with that, it is quite rare to find. Meanwhile, 2-pole breakers highly assure availability. And, you often will get 240 volts between them. 

At the same time, users have started using duplex or tandem while a full panel exists. Having this issue indicates checking out the quadplex breakers. 

Meanwhile, these breakers might come up with a 2-pole. This might fit in the mid part and two singles on the outer side. 

On the other hand, there is a possibility of having a 2-pole breaker on the inside. Along with that, the outside part should contain another 2-pole breaker. 

Reason 2: Having AFCI or GFCI

Siemens tandem breakers are often found in older breaker panels. Interestingly, most of those do not hold enough space for all the required standard circuit breakers. 

However, several new constructions contain most residential circuits. Along with that, AFCI or arc-fault circuit interrupter protection is there.

But no tandem breakers prefer this protection shown by special AFCI circuit breakers. And, this issue is the key contrast compared to other breaker types. 

This protection is offered by special AFCI circuit breakers, which are not offered in tandem styles. In this manner, GFCI models are also currently available in the tandem breakers. 


Unable to fit the right position of tandem breakers leave key reasons like this. When a technician starts fixing this, conducting everything per law is mandatory. 

Meanwhile, you require the exact restorations or upgrades to your existing electrical system. 

Along with that, AFCI and GFCI- both are required by the current code. To fix this, removing the Siemens tandem breakers is an ideal option indeed. 

As a result, allowing code-required AFCI circuit breakers will be easier. Along with that, some fairly significant changes should need to be made. 

In this way, you will see all the circuits get fitting. In the meantime, installing the subpanel or even the main service panel can be easily executed.

Reason 3: Flat Bus Bars

Bus bars are concrete metal bars utilized to hold current. In terms of variety, these bars appear from flat to even rigid.

When accessing the panel to visibly see the bus bar, ensure that the panel isn’t energized. There are some home line load centers where not every spot is tandemised. 

However, you might find copper pipe coating in some parts of the panel. Get the best copper pipes from our recommendation!

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Meanwhile, solder not clinging to copper pipe might affect the panel in the panel. That’s another case though!

But in this case, the spots going to be tandemised locating differently than regular times. You will find them on the opposite part of the main breaker.

So, these are spots to check carefully. As a result, several bottom spots of the load center will be there. Spots having an uneven notch in the center will accept a Siemens tandem breaker. 

In the meantime, there are a few spots carrying flat bus bars. Those are unable to permit tandem breakers. As a result, the breaker won’t fit there.


Let’s find the solution step-by-step!

  • Turn off the main breaker. Also, get a partner to assist you.
  • Now, drag the panel cover screws from the electrical panel. Once you remove it, the inner wires will get exposed. You will find several white and copper wires attached there.
  • Label the wiring in the panel by using tapes and markers. As a result, you can replace them in numerical order after removing and replacing the bar.
  • Now, clear all of the labeled wires out from the bus bar utilizing a screwdriver.
  • Remove the screws mounted at the end of the bus bar and the panel too.
  • But never forget the orientation of the old bus bar. The newer bus bar you set up soon will require this orientational information.
  • Finally, install the new bar. Ensure that the bar is mounted firmly inside the breaker box.
  • Reinstall all of the old wirings to their earliest locations.

And then, replace the cover on the panel cover. Finally, turn on the power to the main breaker.


Can I Utilize A GE Breaker In A Siemens Panel?

Siemens breakers can be employed in GE circuit breaker boxes. Matching the length and voltage prerequisites is a must while utilizing Siemens breakers. It generally can prevent dangerous results, unlike wrong breakers. As a result, this breaker will not fail to break while a surge is ongoing.

How Can I Know Whether My Panel Accepts Tandem Breakers Or Not?

First of all, check the labeling of the manufacturer. It’s visible on the inner face of your panel door. The label should demonstrate how many you can utilize while the panel accepts tandem breakers. It also portrays the slots where you can utilize them. Many panels permit tandems on two or four slots.

What Other Breakers Are Compatible With Siemens?

Several Siemens are the standard interchangeable plug-on-based breakers. Siemens QP, QT, QAF, and QPF are the significant ones among those. These breakers can be used in load centers under several brands. Along with that, it suits most of the Midwest Power and Milbank Mfg metering equipment.

Final Words

Now, you know the key reasons behind Siemens tandem breaker won’t fit! Hopefully, our research in this article will teach you new things regarding this issue. 

Still, have queries on your mind? Feel free to let us know!

With this, we bade farewell to you!

Catch you another day!

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