Tariff switch

Switched on, three-pole tariff switch mounted on a top-hat rail with yellow adjusting screw and opened, non-sealed, transparent cover cap; Setting range 40–50 A, rated current set to 40 A; Some installation space is free to the left and right of the tariff switch that has not yet been provided with blind covers so that the horizontal top-hat rail is visible in the background

two switched on, three-pole tariff switches mounted directly next to each other, each with a light gray adjusting screw and sealed, transparent cover cap; Setting range 16–25 A each, rated current set to 20 A; Blind covers are fitted to the left and right of the two tariff switches

A tariff switch ( English Tariff switch ) is a switching device , the voluntary or tariff current limiting in the electrical installation of consumer equipment used. It is a special miniature circuit breaker whose rated current (or tripping current) can be set within a certain range. The adjusting serving operating element (adjusting screw) is by screw and rotatable with a sealable provided cap in order to prevent unauthorized adjustment. A tariff switch can also be easily and safely switched off and on again by non- electrical engineers .

application areas

Tariff switches are mainly used as pre- or post- meter fuses . This is the part of the power supply company (PSC) is possible, which allowed level of network usage (subscription rights), depending on the power grid - access contract between RU and customers can set (within the setting of tariff switch used) quickly and easily, without having to replace components. This can save work and / or costs.

Occasionally, tariff switches are used instead of ordinary, slow-acting circuit breakers.

properties

Designs

Tariff switches have a plastic housing. They are designed as rail- mounted devices and can be mounted close together on a 35 mm top hat rail .

Tariff switches are available in single- pole and three- pole versions, each with a space requirement of 1 module (TE) or 3 TE. The single-pole versions are intended for use in single-phase alternating current networks, the three- pole versions for three-phase alternating current networks.

Installation

If a higher current (especially in the area around the upper setting value) flows through the tariff switch over a long period of time (several tens of minutes) , it warms up noticeably. Since some tariff switches the trip current decreases with increasing device temperature, it may be useful to leave between the immediately adjacent modular devices some free space, so that the resulting waste heat of large radiating and convection in the distribution box can be better dissipated and thus no unwanted automatically shut off the Tariff switch comes.

Switching behavior

Even three-pole tariff switches only have one adjusting screw. The set rated current applies to each of the three phases ; the setting can only be made jointly for all three phases. If the rated current, for example, to 20 amperes is adjusted, can (in Europe at the usual mains voltage ) three-phase on period of up to about 3 x 20 A × 230 V = 13.8 k VA to apparent power seen; devices with a maximum connected load of 13.8 kVA can therefore be operated.

With three-pole tariff switches, the switching function is coupled for all three phases. This means,

when the tariff switch is switched on manually, all three phases are switched on simultaneously and
All three phases are switched off simultaneously when the tariff switch is switched off manually or when the tariff switch is triggered.

Trigger mechanism

The triggering, i.e. the internal shutdown, takes place as soon as an excessively high current is detected in at least one of the maximum three phases. The tripping criteria are (as with an ordinary miniature circuit breaker)

On the one hand, there is protection against overload, which is implemented by a slow, thermal release ( bimetal switch) that is triggered when the current flowing through the tariff switch is significantly exceeded for a longer period of time (depending on the make: around 1.2 to 1.45 times the set rated current for less than an hour), as well as ${\ displaystyle I _ {\ text {e}}}$
on the other hand, the short-circuit protection, which is implemented by an electromagnetic quick release.

The manual actuation of a tariff switch is carried out using a lever that latches in both end positions (on / off). The release mechanism in the key switch ensures that internal triggering cannot be prevented by externally blocking the switch lever. If and for as long as an internal triggering criterion is met, the result is that the lever does not engage in the on position.

Tripping characteristic

Time-current characteristics (in double logarithmic representation ) for the tripping characteristics B, C and D

Tariff switches have the tripping characteristic D (or a similar one), which means that selectivity to subsequent miniature circuit breakers, which in turn usually have characteristic C or B, can be achieved.

Setting ranges

Tariff switches are usually available for the following setting ranges with regard to the rated current, although generally not every manufacturer covers all of the listed ranges with its range:

13-20 A
16-25 A.
20-32 A.
25-40 A
40-50 A
40-63 A
50-63 A

Circuit symbols

Circuit symbol of a three-pole tariff switch

Circuit symbol of a single-pole tariff switch

In the illustration of the circuit symbol of a three-pole tariff switch, the connection terminals are symbolized by small circles. The terminals are usually numbered consecutively with the numbers 1–6, whereby terminals 1 and 2, 3 and 4, and 5 and 6 each form a separate current path.

The lever for manually operating the tariff switch can be seen at the top left, based on the shape of a horizontal " T " rotated 90 ° counterclockwise . This lever leads to the release mechanism (switch lock), which is represented by a four-part square.

The top horizontal dashed line connected to the trigger mechanism extends over all three switches and symbolizes that the switching function is coupled for all three phases. All three switches are therefore always operated synchronously. The dashed lines in the left area indicate that the thermal overload protection and the magnetic short-circuit protection also have an effect on the tripping mechanism.

The rectangular loops (in the upper row of rectangles) represent the bimetal releases of the thermal overload protection. The symbols " " (lower row of rectangles) are intended to symbolize the magnetic quick release that triggers when a multiple (approx. 10–30) of the set rated current is exceeded. The letter " " stands for the symbol of the electrical current strength, and the greater-than symbol " " is intended to represent the need to exceed a threshold value. ${\ displaystyle I>}$ ${\ displaystyle I}$ ${\ displaystyle>}$

Since with three-pole tariff switches each of the three phases is monitored and switched separately, switches, thermal and magnetic triggers are available in three versions, whereas with single-pole tariff switches there are only simple ones.

Norms and standards

Relevant norms and standards for tariff switches are:

EN / IEC 60898-1
EN / IEC 60947 ( use categories )

equipment

As accessories for tariff switches there are - depending on the manufacturer - various attachments such as B. shunt release , undervoltage release , auxiliary switches and reclosing devices .

Demarcation

Motor protection switches with setting options and adjustable miniature circuit breakers are also commercially available - similar to tariff switches . In contrast to tariff switches, the setting screw for the rated current in the two last-mentioned devices is not provided with a cover cap; the adjusting screw cannot be sealed here.

Web links

Commons : Tariff Switch - Collection of pictures, videos and audio files

Individual evidence

↑ Datasheet - Z-TS25 / 1. Eaton Industries , 2019, accessed April 27, 2019 .
↑ Tariff switch range. Schrack Technik , accessed on April 27, 2019 .
↑ Tariff switch C60H-TA. (PDF; 213 KB) Multi 9 - C60 series. Schneider Electric Austria, September 3, 2008, accessed April 27, 2019 .
↑ Installation switching devices (xPole). (PDF; 6.7 MB) Eaton Industries , July 27, 2017, pp. 343–345, 350 , accessed on April 27, 2019 .
↑ Catalog installation devices. (PDF; 21.1 MB) Eaton Industries , January 7, 2016, pp. 59, 63, 69–79 , accessed April 27, 2019 .
↑ Motor protection switch range. Schrack Technik , accessed on April 27, 2019 .
↑ Installation switching devices (xPole). (PDF; 6.7 MB) Eaton Industries , July 27, 2017, pp. 343–349 , accessed on April 27, 2019 .

[1] Datasheet - Z-TS25 / 1. Eaton Industries , 2019, accessed April 27, 2019 .

[2] Tariff switch range. Schrack Technik , accessed on April 27, 2019 .

[3] Tariff switch C60H-TA. (PDF; 213 KB) Multi 9 - C60 series. Schneider Electric Austria, September 3, 2008, accessed April 27, 2019 .

[4] Installation switching devices (xPole). (PDF; 6.7 MB) Eaton Industries , July 27, 2017, pp. 343–345, 350 , accessed on April 27, 2019 .

[5] Catalog installation devices. (PDF; 21.1 MB) Eaton Industries , January 7, 2016, pp. 59, 63, 69–79 , accessed April 27, 2019 .

[6] Motor protection switch range. Schrack Technik , accessed on April 27, 2019 .

[7] Installation switching devices (xPole). (PDF; 6.7 MB) Eaton Industries , July 27, 2017, pp. 343–349 , accessed on April 27, 2019 .