Grounding a bathtub in an apartment: why and how to properly ground a bathtub

Due to the fact that electrical appliances in the bathroom are constantly exposed to high humidity, the bathroom is considered one of the most dangerous places in the apartment from a safety point of view. Any electrical device can cause current leakage.

And if someone touches a live object, the consequences can be disastrous. Grounding a bathtub in an apartment is a simple procedure, but it can save a person’s life and health. It is this question that we will consider in our article. Let us examine in detail the reasons why grounding is necessary.

We will also provide detailed instructions on how to ground your bathtub yourself, supplementing the material with visual photos and video recommendations.

What is grounding and why is it needed?

Before starting work, you need to understand the theoretical part of the issue. What does the very concept of “grounding” mean, is it really so necessary and why is this issue so acute in the bathroom. This knowledge will help you figure out whether you really need to ground the bathtub in your apartment.

Explanation of the concept of "grounding"

Electric current is a rather dangerous thing, especially if handled improperly.Needless to say, when combined with water, completely harmless electrical appliances get out of control and become deadly.

From the physics course we know that current always moves along the path of least resistance. The purpose of grounding is to work in such a way that even if an electrical appliance unexpectedly breaks down, the person who is near it at that moment does not suffer.

If you grab “0” with one hand and the phase with the other, the body will become a conductor between different potentials and current will flow through it

The earth can act as zero potential. This property makes it possible to safely use electricity at home. “Grounding” means connecting the electrical wiring network to the ground with a suitable conductor.

It is often quite difficult to perform such an operation in apartments, especially in high-rise buildings. They use another method - zeroing.

Grounding performs the same function as grounding, but diverts the current not to the ground, but to “0”. That is, the body of the device is connected to zero, and in the case when current flows through the body, a short circuit occurs and the machine is knocked out

This is a fairly popular method, but there is a significant drawback. The machine does not work instantly. That is, between a theoretical electric shock and knocking out RCD Some time passes, even just a few fractions of a second. If the voltage is high and the path of electric current passes through the heart, even a second can become fatal.

It is much safer to be grounded, although it is more difficult to implement. The potentials in the circuit formed at the moment of breakdown (between phase and ground) are equalized instantly, and nothing threatens the person.

Why do you need to ground a bathtub in an apartment?

Based on the above, grounding bathroom appliances is a common safety measure that should be done by default. Unfortunately, proper grounding is rarely found in modern apartments. Not everyone fully understands what it is and why it is needed in the bathroom.

Previously, when water pipes were exclusively metal, the issue of grounding did not arise at all. Without exception, all the baths were somehow connected to the pipeline, which, in turn, went underground, thus creating the same grounding.

Now steel pipes are being abandoned in favor of plastic ones. Even if you still have a metal pipe, you cannot be sure that the neighbors below have not changed their part of the riser, thus breaking the chain. Therefore, it is better to play it safe and protect yourself and your family.

If you decide to ground your bathtub, you should consider connecting other dangerous surfaces and devices to the ground: pipelines, water heaters, etc.

In addition, in those days when many apartment buildings were built, there were practically no electrical appliances in the bathroom. Even a basic socket was rare.

Now in the average bathtub you can count about 5 constantly operating electrical appliances:

• electric water heater;
• washing machine;
• heated towel rail;
• hair dryer;
• electric razor

Any of these and other devices can cause voltage on its body. The consequences can be dire. It is better not to neglect the grounding device even before dangerous situations arise.

Features of grounding bathtubs made of different materials

Steel or cast iron bathtubs are an excellent conductor.It is these models that need to be grounded first. Old-style bowls are connected with a grounding wire to a metal leg. To do this, a hole is drilled in the latter and a special plate is installed - a grounding jumper.

More modern models are already equipped with an overlay on the body - a petal - even at the stage of release from the factory.

The grounding jumper must be well welded or screwed to the bathtub. Poor contact between the ground wire and the surface of the bowl may cause the ground to fail

An acrylic bathtub is made of a polymer material, which itself is not a conductor of electric current. However, acrylic tends to accumulate static electricity.

Some models are designed in such a way that the bowl is supported by a steel or aluminum frame, which must be grounded.

A couple of turns of copper stranded wire, twisted a couple of times around a pre-cleaned water supply, heating, or sewage pipe, are perfectly fixed with a clamp - the rubber prevents the oxidation of the surface

Hydromassage baths or Jacuzzis are equipped with a system of jets through which water is supplied at different pressures. To make the bath work, you need a pump. And it is powered from a 220 V electrical outlet.

In addition to the mandatory rules for connecting this type of bathtub, such as safe installation of sockets in the bathroom (no closer than half a meter from the edge of the bowl and the ground level and protection not lower than IP44), be sure to ground the bath itself, just in case.

DIY grounding instructions

When everything fell into place with theory, it’s time to start practicing. The issue of grounding in an apartment can become a serious problem if the house does not have a grounding loop. But this can be easily fixed if you have the desire and opportunity. Select the right materials and tools, and then start installing the wire.

Step 1 - choosing materials before starting work

First you need to decide what materials to purchase for electrical work. After all, you definitely need to choose the right cross-sectional area of ​​the wire, its type, and not make a mistake with the amount of consumables.

It is important to choose the correct wire. As a rule, there is no need to reinvent the wheel. Ready-made copper grounding cables with a cross-sectional area of ​​6 mm. sq. in yellow-green insulation are sold in any hardware store in the electrical department

In addition to this basic element, you will need:

• potential equalization box;
• RCD for the required number of Amperes;
• terminals;
• pipe clamps.

The potential equalization box is a plastic compartment in which all branches of the ground wire are connected.

Since it is prohibited to ground objects in series, a separate cable must go from each device or pipe to the potential equalization box (PEC).

The residual current device completely cuts off the power to the circuit. Typically, each room is connected to a separate machine. In the event of an accident in the bathroom, only the corresponding area will be knocked out, and not the entire apartment

The RCD (residual current device) is not installed in the bathroom. Its place is in the corridor or other dry, safe place. It is advisable to familiarize yourself with possible schemes and rules for connecting RCDs.

For apartments, a 10 or 16 A RCD is most often chosen, but if you have high-consumption electrical appliances, such as an electric oven or a high-performance instantaneous water heater, such protection may not be enough. We advise you to look at practical recommendations on selection of RCD.

A couple of turns of copper stranded wire, twisted a couple of times around a pre-cleaned water supply, heating, or sewage pipe, are perfectly fixed with a clamp - the rubber prevents the oxidation of the surface

Above mentioned terminals - these are special connections that allow you to carefully and “civilly” connect the wire to the bath petal. This type of connector comes in a variety of shapes.

Clamps are needed for those cases when, in addition to the bathtub, you want to separately ground the pipeline.

Step 2 - preparing tools for electrical work

The set of necessary tools for laying grounding in the bathroom is not very different from the standard set of an electrician.

You don’t have to buy anything new or specific, just take care of:

• screwdriver;
• wrench;
• drills and drill bits for metal;
• flashlight;
• tester or multimeter;
• welding machine (optional);
• protective equipment (extremely necessary).

The most common tool in a home craftsman's toolbox is a screwdriver. It is better to perform electrical work with an indicator screwdriver. It has a hidden light in the handle that lights up if you touch a live element with a screwdriver.

You can make a hole in the influx of a cast iron bathtub using a metal drill and a drill. Do not forget about the increased fragility of this metal, so you need to work with great care

A wrench is needed to tighten the bolts when connecting the ground wire to the metal plates.

A drill will be needed if the manufacturer does not provide a special hole for connecting the cable or the bathtub model is too old.

The bathroom is a poorly lit place. Since work with electricity is carried out only when the power is turned off, working without a flashlight in a dark room will be extremely inconvenient

A tester or multimeter is a device that allows you to measure the voltage in a circuit. It is especially important to have one of these devices when you do not know for sure whether your outlet is grounded or not.

You will need a welding machine when you decide to install a grounding loop outdoors.You need to weld a steel structure reliably; if you do not have experience and appropriate skills, a welding machine may not be enough; you will also need a qualified welder.

All sorts of instructions, posters and documents on electrical installation work never tire of reminding us about protective equipment. But nevertheless, cases of electric shock during the repair of a simple socket or installation of an RCD occur with enviable regularity

Before grounding the bathtub in your apartment, prepare tools only with handles made of dielectric materials, additionally check the presence of voltage in the circuit even when the power is turned off, hang a notice on the electrical panel warning about the work so that someone does not accidentally turn on the machine.

Step 3 - laying a grounding bus for the apartment

Ideally, an apartment building should have a common grounding bus to which any resident can connect and ground. In practice, general house grounding is a huge success; it is very rare.

If you are lucky and the management company of your home, the developer or active residents who are aware of the dangers and responsibility of using electrical appliances in the bathroom have installed a grounding loop, you can connect all your dangerous electrical appliances, metal pipes and the bathtub directly to it through the electrical panel on the floor.

The main grounding bus has the form of a plate to which all grounding cables are connected at the terminals. This simplifies wiring and reduces the chance of unplugging the wrong wire and causing other confusion. Since all the cables are the same color, it is quite easy to mix things up

If no one has taken care of your home yet, you will have to do it yourself.

And there are several options:

• ask the management company or city authorities to do the grounding;
• convince other residents and pay for installation from your own pocket;
• take care of your safety and make an individual grounding loop on your own.

In the last two cases, you will need to run a copper wire at least 6 mm2 thick along the entire riser all the way to the basement.

Then, near the house, in an open, preferably fenced and deserted area, a pit is made about 1.5 m deep. Three thick electrodes are placed vertically in this pit - most often rolled steel or fittings are used.

In fact, it is not necessary to make the ground electrode in the shape of a triangle. Three strip-shaped electrodes will do the job perfectly. Traditional triangular shape takes up little space, simplifies excavation and ensures good contact

The three racks are connected at the top with a steel strip using a welding machine or a thick wire to form a closed triangular contour.

Then the grounding wire is removed and laid underground in a special protective sleeve. The wire is connected to the metal structure. This creates a common, fairly reliable and durable grounding circuit that can be used by all residents of apartments along the riser.

The stages of installing a grounding loop next to a high-rise building are similar to installing such a loop in a private house. If you still decide to make it yourself, we recommend that you familiarize yourself with useful tips on circuit design and installation.

Step 4 - Grounding all appliances in the bathroom

Once you have verified that your home has a ground and found how to connect to it, the further process will not be difficult.

1. Select a location for the potential equalization box. It should be located on a dry wall, at a distance from the bath.
2. If the bathtub is new, it should be turned over for convenience. Often people think about grounding when the bathtub is not only installed, but also covered with facing tiles, hidden behind a screen or decorative panel. Then it will be a little more difficult to do the job.
3. Decide exactly where the cable will be connected. Find the location provided by the manufacturer. As a rule, this is a plate with a hole, welded or screwed to the body.
4. If there is no special grounding point, you need to use a drill. Drill a small hole in the metal part. If it is cast iron, most likely there are ridges at the bottom of the bowl, which should ensure the stability of the structure on the legs. These sagging can be used for grounding.
5. Lay the wire along the wall from the connection point to the control panel.
6. Using a terminal, connect one end to the plate in the potential equalization box, and the other to the bath body through the drilled hole.
7. Connect the PMC to the grounding bus in the electrical panel with a copper wire of sufficient thickness.
8. Then you need to check the correct connection and hide the wire. This is done not only for aesthetic purposes, but also to avoid accidentally damaging the cable.

After installation is complete, you need to check the grounding operation using a tester. To do this, connect the phase and the grounded bath. If the tester light is bright, it means that current will flow through this circuit in the event of an accident and will not affect a person.

Conclusions and useful video on the topic

Videos with answers to most popular questions will help you finally close the question of the need for grounding in the bathroom. If it is easier for you to perceive information in video format, this collection will certainly help you.

Why ground a steel bathtub in an ordinary apartment:

How to organize grounding in an apartment building:

How to make grounding in the bathroom:

After all of the above, it becomes clear why ground a metal or acrylic bathtub. Usually this work takes very little time, provided there is a common house grounding. A few simple steps - and your bathroom becomes a safe room without the threat of electric shock.

Are you wondering whether you need to ground your bathtub? Or are you already planning to do grounding, but you have questions that we did not cover in this article? Ask them in the block below this article.

Or do you have theoretical knowledge of bathtub grounding and want to share it with other users? Maybe you noticed an inaccuracy or error in our article? Write to us about it in the comments.