Installation of Elektrobock timer switch on DIN rail CS4-16

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Installation of the Elektrobock timer on a DIN rail CS4-16: complete professional guide

A timer on a DIN rail is one of the most reliable ways to automate electrical appliances in a home or business – from water heaters, circulation pumps, outdoor lighting to various technological circuits. The model CS4-16 from Elektrobock is a single-phase weekly timer intended for direct installation in a distribution box, and precisely the installation in the switchboard is the question that stops many homeowners and craftsmen. In this article, we will go through the entire process in detail – from tools and safety regulations, through physical mounting on the DIN rail, electrical connection diagram, setting the clock and programming to common errors that we repeatedly see in orders.

What is CS4-16 and where is it used

CS4-16 is a digital weekly timer from the Slovak manufacturer Elektrobock. The digit 4 in the designation indicates that it is a series intended for mounting on a standard DIN rail (EN 60715 TH35, i.e. 35 mm), and 16 indicates the maximum contact current – 16 amperes at 230 V AC. The power of the load that it can switch directly thus reaches up to 3,680 W on resistive loads (heaters, light bulbs) or typically 1–2 kW on inductive loads (motors, pumps) – it depends on the cos φ of the load.

The switch has a built-in backup: an integrated capacitor (supercap) or lithium battery maintains the program and clock during a power outage for several hours, or days – the exact backup time is found in the technical sheet of the respective version. The display is an LCD with backlighting and the control is done via four buttons. The interface is also available in Slovak or Czech according to the menu setting.

Typical applications of CS4-16 in practice:

Switching a water heater for hot utility water (boiler 2–3 kW) – the switch controls a cheap tariff or night heating
Controlling a circulation pump of central heating according to a daily schedule
Outdoor lighting – driveway, garden, façade lights
Ventilation: switching a recuperation unit or axial fan at set hours
Advertising LED panels in shops – automatic switching on/off
Tempering a garage or warehouse – switching on a convector only during working hours

If you are looking for a solution without a switchboard – for example for a socket in the living room or for direct connection under a switch – Elektrobock offers smaller switches such as timer under switch CS3-1 or CS3-2 with a weekly program. A comparison of both types of solutions can also be found in the article Timer under switch vs. on DIN rail: which type to choose in this Knowledge Center.

Technical parameters of CS4-16 – what to know before installation

Before you reach for the screwdriver, it is good to have clarity in the parameters. Below is an overview of key values (always check the current technical sheet for the specific purchased batch, the manufacturer may make revisions):

Parameter	Value
Supply voltage	230 V AC, 50 Hz
Max. switching current (resistive load)	16 A
Max. power (230 V, cos φ = 1)	3,680 W
Number of DIN modules (width)	2 modules (36 mm)
Mounting	DIN rail TH35 (EN 60715)
Number of switching programs	42 (on/off pairs)
Minimum switching interval	1 minute
Clock backup during power outage	approx. 100 hours (supercap version)
Protection class	IP20 (only in switchboard)
Operating temperature	-10 °C to +50 °C

Important note for practice: IP20 means that the switch is not protected against moisture or dust. Never install it in damp areas (basement, bathroom, outside) without the switchboard having its own higher protection – at least IP44 or IP65 for exterior cabinets.

Tools, materials and safety regulations before starting

Work in the distribution board is work under voltage – or even worse, work on a source that can unexpectedly activate reverse current. Always comply with the current regulations: STN 33 2000 and STN EN 61439 for distribution boards, and if you are working in another person's building or it is a new installation, the work must be carried out or tested by a qualified person according to Government Regulation No. 508/2009 Coll.

Required tools:

Flat screwdriver 2.5–3 mm (for switch terminals)
Crosshead screwdriver PH2 (for larger terminals)
Insulated pliers, cable cutter
Wire stripper (stripping tool) for cables
Tester (multimeter or phase tester)
Drill or impact driver, if you need to expand space in the distribution board
Label pen or printer for DIN labels – we recommend always labeling the installation

Materials:

CS4-16 (the switch itself)
Wires min. 1.5 mm² CY or CYKY for power supply and load (for 16 A we recommend 2.5 mm²)
Wire ferrules – their use in the distribution board is a standard of good practice
Fuse or circuit breaker before the switch (max. 16 A, type B or C depending on the load)
Neutral bar and PE bar, if the distribution board does not have them yet

Before any manipulation in the distribution board:

Switch off the corresponding circuit breaker and LOCK it (shim, lock, label "DO NOT SWITCH ON – work in progress")
Measure with a phase tester to ensure that the wires you are touching are actually de-energized
Work in dielectric gloves, if the entire distribution board is not disconnected from the grid

Physical mounting on DIN rail – step by step

The actual mounting of CS4-16 on the DIN rail is mechanically simple and takes literally a minute, but you need to know a few details to ensure the switch is securely mounted and can later be removed without damaging other components in the distribution board.

Step 1: Preparing space in the distribution board

CS4-16 occupies 2 DIN modules, i.e. 36 mm in width. Check whether you have free space in the distribution board. If you are installing the switch next to existing circuit breakers, leave at least a small gap (5–10 mm) for air circulation and easier access to the terminals. If the distribution board does not have a DIN rail (old type of distribution board with screws), or the rail is full, you need to either install a new rail or choose another solution.

Step 2: Mounting on the DIN rail

Each DIN module has two plastic clips on the back side – one fixed (upper) and one spring-loaded (lower). The procedure is simple:

Hold the switch with both hands and slightly tilt it (upper edge forward).
Insert the fixed upper clip (behind the upper edge of the rail) and then press the bottom of the switch toward the rail until it clicks – this is the sound of the spring clip snapping into place behind the lower edge of the rail.
Check that the switch is not tilted and does not overlap adjacent components.

Demounting: insert a flat screwdriver into the recess of the spring clip, press it away from the rail and tilt the switch upward to remove it.

Step 3: Arranging wires before tightening

Before you start inserting the wires, strip them to a length of 8–10 mm and install ferrules. Ferrules are important because they prevent the cable from fraying and ensure a reliable contact in the screw terminal. Without ferrules, the wires from the cable can loosen over time, leading to sparking and fire – in practice, we see cases of burned terminal blocks precisely due to missing ferrules.

Electrical connection diagram CS4-16

The switch CS4-16 typically has four terminals on the bottom side, labeled in the technical documentation. Let's look at the standard single-phase connection:

Description of terminals and connection

Specific terminal labels may vary depending on the manual version, but in principle they are always:

L-in (or 1): input phase (power supply for the switch and load)
N-in (or 2): input neutral conductor (power supply for the switch control electronics)
L-out (or 2/output): switched phase – the wire to the load is connected here
N-out (or 4): load neutral – on some versions N is internally bridged, so it is sufficient to connect N directly to the terminal block

The protective conductor PE never passes through the switch – it runs directly from the PE bar in the distribution board to the load. This is a basic safety requirement that must be followed without exception.

If you are switching a load through an external contactor (e.g., a three-phase motor or a larger heating system), the CS4-16 controls the contactor coil (230 V, low current), not the load directly. In this case, the wire from L-out carries only the control current of the coil – the overall power of the load can be an order of magnitude higher.

Setting the time, date and basic configuration

After the physical connection, the next step is the setting. The first step is always to set the current time and day of the week – without this, the switch will not execute the programs correctly. The procedure for the CS4-16 is as follows (specific steps may vary slightly between firmware revisions, always check the manual included):

After the first power-on, a prompt to set the language or the current time (typically 00:00, Monday) usually appears.
Press the CLK (or MENU/CLOCK depending on the version) button and hold it for 2–3 seconds until the time starts to blink.
Use the arrow buttons (▲▼) to set the hour, confirm with OK or by pressing CLK again.
Set the minutes – same procedure.
Set the day of the week (1 = Monday, 7 = Sunday or 0 = Sunday, depending on the setting).
Confirm. The clock will start running.

If the CS4-16 has a daylight saving time (Daylight Saving Time – DST) function, we recommend activating it for automatic time shift in March and October. This will prevent the boiler or pump from turning on an hour earlier or later after the time change.

Programming switching times – detailed procedure

CS4-16 allows programming up to dozens of switching events (pairs: ON time + OFF time) and assigning them to any combination of days of the week. This is precisely where its great advantage over daily (24-hour) mechanical switches or simple digital switches with daily programs lies.

Creating a new program

Press the PROG (or TIMER) button. The display will show the program number (e.g. P01) and the current setting (day, ON time, OFF time).
Select the days on which the program should be activated: you can set individual days (Mon, Tue, Wed...), groups (workdays, weekend) or every day. Practical tip: for a boiler on a low tariff, you usually set the same every day, so choose "1-7" (all days).
Set the ON time – e.g. 22:00 for night heating.
Set the OFF time – e.g. 06:00 (the next morning). Note: if the OFF time is less than the ON time, the switch will correctly understand that it refers to midnight.
Save the program (OK / PROG).
Repeat for the next program (e.g. a short heating in the afternoon 14:00–16:00).

Practical example for a family house: The customer had a 200-liter boiler (2 kW). We configured two programs: main night heating 22:30–05:30 (low tariff DD5), and an additional program on Sunday 13:00–16:00 in case the family stays at home longer. Result: a reduction in electricity consumption by ~15 % compared to the previous solution with a mechanical switch, where reheating occurred even during peak hours.

Viewing and editing existing programs

Pressing PROG allows you to navigate between programmed events. Empty program slots are usually marked as „- - : - -". To edit an existing program, select it and press OK, then proceed as with a new program. To delete a program, set the times to „- -:- -" in the program menu or use the DELETE/CLR function if available.

Manual (hand) switching on/off

Even though the CS4-16 has programmed times, you can manually switch the load at any time by pressing the MAN (Manual/HAND) button. Typically, the switch cycles between three states: AUTO (program active) → ON (permanently on) → OFF (permanently off) → AUTO. This override is useful, for example, when guests arrive and you want hot water immediately without waiting for the program to activate.

Practical scenarios from installation practice

Scenario 1: Switching on a circulation pump

A circulation pump for central heating typically has a power of 25–80 W – trivial load for the CS4-16. The problem is, however, the inductive load and frequent switching. For a customer in a family house, we set up 4 switching intervals per day (morning 06:00–09:00, noon 11:30–13:00, afternoon 16:00–21:30, night off). Result: the pump runs only when the house is actually in use, and the pump consumption dropped by 60 % compared to the previous state, where it ran 24 hours a day.

Scenario 2: Outdoor garden LED lighting

LED reflectors with a total power of 600 W – purely resistive load, ideal for the CS4-16. Program: Monday–Friday switching on at 17:30 (in winter) or 20:00 (in summer), switching off at 23:00. On the weekend, extended to 00:30. The customer appreciated that he did not have to worry about manually switching off and did not pay for lighting he might have forgotten to turn off.

Scenario 3: Electric heater in the garage

A small 1 500 W heater in the garage – switching on during working days from 05:30 (before going to work), switching off at 08:00. On the weekend, a different program: 07:00–10:00. The CS4-16 handles such a load without problems, the current is only ~6.5 A at 230 V. It was important to install the distribution board in the garage with IP55 protection against dust and moisture – the switch itself, CS4-16 with IP20, had protection via a cabinet.

Scenario 4: Controlling a contactor for a three-phase heater

When the customer had a three-phase pool heater of 9 kW, the CS4-16 controlled the coil of a Siemens 3RT three-phase contactor (230 V coil, power ~10 W). The switch output only loaded a few milliamps – the power ratio was ideal. The CS4-16 had a programmed night heating for the pool, the contactor switched the full power. This solution is elegant and safe when the load exceeds the direct switching capabilities of any DIN rail-mounted timer.

Comparison with other Elektrobock switches

CS4-16 is not always the right choice. Let's briefly look at the alternatives from the Elektrobock portfolio:

CS3-1 and CS3-1B – switch under a classic switch (wall box), daily program, maximum current 8 A. Suitable for lights, fans, which are controlled locally by a switch. Installation without a distribution board, but limited power and only daily (not weekly) program.
CS3-2 – under a switch with a weekly program, 10 A. A compromise between the comfort of the distribution board version and the simplicity of installation.
CS3-4 – extended version under a switch, 16 A, suitable for more demanding loads directly in wall installation.
Remotely controlled socket WS101 – a solution without fixed installation, plug-and-play, remote control, maximum current 16 A. Suitable for portable appliances or places where you do not want to interfere with the electrical installation.

A detailed comparison can be found in the article How to choose the right Elektrobock timer for the household and What maximum power can an Elektrobock timer or socket handle – these topics are part of this Knowledge Center and we recommend reading them before making a final decision.

Most Common Installation Errors for CS4-16

Over years of field experience, we have observed several recurring errors:

Reversed L-in and L-out terminals: The switch may still work, but the contact may remain under voltage during manual switching off. Always check the wiring diagram before powering on.
PE conductor routed through the switch: The protective conductor must not be interrupted – it must not pass through the switch or through any device.
Insufficient conductor cross-section: For a load of 16 A, a minimum of 2.5 mm² is required for fixed installation (CYKY). A thinner conductor may overheat.
Lack of ferrules on stranded conductors: See above – this may cause the connection to loosen over time.
Incorrect weekday setting: The most common issue after the first installation. The switch turns on on the wrong day. Check: is "1 = Monday" or "1 = Sunday" set? This depends on the version.
Ignoring the clock backup: After a long power outage (several days), the clock may drift – after the power is restored, check the current time on the display and correct it if necessary.
Installation without a circuit breaker: CS4-16 must be protected by a circuit breaker. Without it, in the event of a load short circuit, the switch or even a fire may be damaged.

Maintenance and Lifespan

CS4-16 is an electronic device with a mechanical relay as the power component. The relay contacts have a certain number of switching cycles (typically 100,000 – 300,000 cycles at rated load). For loads such as a water heater (1–2 switching operations per day), this corresponds to several decades of operation. For applications with multiple switching operations per day (e.g., heat recovery with short cycles), we recommend checking the contacts once a year – signs of wear include sparking, sounds during switching, or noticeable heating of the switch.

Regular maintenance: Check once a year if the conductors in the terminals are securely tightened – thermal fatigue of metals and vibrations can loosen the conductors. If the switch repeatedly shows errors (incorrect switching, missing program), first reset the device according to the instructions (RESET/FACTORY), and if the problem persists, read the article Common faults of Elektrobock timer switches and their solutions.

Frequently Asked Questions (FAQ)

Can I connect a three-phase appliance to CS4-16?

Not directly. CS4-16 is a single-phase switch (230 V / 16 A). For three-phase appliances, you must use an external three-phase contactor – CS4-16 switches its control coil (230 V). The load capacity is then limited only by the contactor parameters, not by the switch itself.

What happens to the set programs during a power outage?

CS4-16 has an internal backup (supercapacitor or battery) that maintains the clock and programs during a power outage. For short outages (hours to tens of hours), the programs are preserved. During a very long outage (several days), the clock may fail – after power is restored, check the current time on the display. The programs (switching events) are stored in non-volatile memory and will survive even a long power outage.

What type of circuit breaker should I use before CS4-16?

Use a circuit breaker with a rating corresponding to the load, but no higher than 16 A (which is the switch limit). For resistive loads (boiler, heater), use type B, for inductive loads (motor, pump) use type C. The conductor must have a minimum cross-section of 2.5 mm² at maximum current of 16 A for fixed installation.

Can I use CS4-16 with LED lighting or energy-saving lamps?

Yes, without problems. LED loads are mostly low-impedance with low power – for CS4-16, this is a trivial load. Be careful with the minimum load: some very old switches had a minimum load requirement (to ensure the contact "fired" properly), but the modern relay in CS4-16 does not have this issue. If you switch only a few watts of LED, everything will work without limitations.

How do I reset CS4-16 to factory settings?

The procedure depends on the firmware version. The most common method: in the menu, look for the RESET or CLEAR ALL (VYMAZAT VŠE) option. Alternatively, hold the PROG + MAN

Do you have a question about this topic?

Not sure or dealing with a specific situation in your home? Write to us – we are happy to help.