Eltom - UWS-EL, UWA-EL - 3-pole indoor earthing switches

Earthing switches UW-EL can be used indoor with voltages from 12 to 24 kV and short- circuit currents from 16 to 31.5 kA/1 s. Earthing switches type UWA-EL and UWS-EL have the ability to conduct short-circuit currents, thus protecting both the operator and the switching equipment.

Each earthing switch is equipped with a spring mechanism, which makes the closing of the circuit independent of the speed of manual manoeuvring. You can freely choose the operating side of the earthing switch and the direction of current flow, except for a few variants combined with current transformers.

Earthing switches type UWA-EL are apparatus earthing switches. Permanent contacts are attached to another device, e.g. a disconnector or a current transformer. Earthing switches type UWS-EL are stationary devices, equipped with insulators, on which permanent contacts are mounted. In this case, the connection can be either rail or circular.

In the earthing switches UWS-EL it is possible to install insulators with the signaling module SC or SR.

The base of the earthing switches is made of galvanized steel sheet, the conductive elements are made of silver plated copper elements, the insulators are made of epoxy resins.

TYPE	DIVIDER	RATED VOLTAGE	SHORT CIRCUIT CURRENT	SHORT-CIRCUIT IMPULSE CURRENT	TORQUE - OPEN POSITION	TORQUE - CLOSE POSITION	WEIGHT
UWS – EL – 12 UWA – EL – 12	150, 170, 210	12 kV	25, 31,5 kA/ 1 s.	40-80 kA	90 Nm	50 Nm	14/17 kg
UWS – EL – 17,5 UWA – EL – 17,5	180, 210, 275, 300	17,5 kV	25, 31,5 kA/ 1 s.	40-80 kA	120 Nm	50 Nm	15/18 kg
UWS – EL – 24 UWA – EL – 24	210, 275, 300	24 kV	25, 31,5 kA/ 1 s.	40-80 kA	140 Nm	50 Nm	17/20 kg

rated frequency: 50, 60 Hz
ambient temperature: -40˚C up to +60˚C

RATED VOLTAGE	TEST WITHSTAND VOLTAGE 1 min, 50 Hz	TEST IMPULSE VOLTAGE 1,2/50 µs
12	28 (42 GOST)	75
17,5	38	95
24	50	125

Auxiliary contacts can be installed on both the left and right side of the earthing switch. The connector may have five or ten pairs of auxiliary contacts NO / NC. The WK 5/10 limit switches are used in one of configurations presented on the connection diagram.

Connection diagram

PN-EN 62271-102:2005/AC:2005
PN-EN 62271-1:2009

The earthing switches have different configurations. Depending on customer requirements, marking can be as follows:

TYPE

RATED VOLTAGE Un [kV]

SHORT-CIRCUIT CURRENT 1 s. Ik [kA]

DIVIDER [mm]

UWS

UWA

12

17,5

24

25

31,5

Z

150

170

180

210

275

300

EXAMPLE:

UWS 24/31,5/Z/210:

Stationary earthing switch, voltage 24 kV, short-circuit current 1 s. 31,5 kA with divider of 210 mm.

Dimensions of earthing switch UWS-EL

UWS	Z	A1	A2	A3	B1	B2	B3	C1 (25)	C1 (63)
24/25 \| 24/63	170	366	529	538	316	360	434	370	350
	210	446	609	618	316	360	434	270	350
	275	576	739	748	316	360	434	360	307
	300	626	789	798	316	360	434	360	307
17/25/Z \| 17/63	210	446	609	618	316	360	412	345	345
	275	576	739	748	316	360	412	335	310
	300	626	789	798	316	360	412	335	310
12/25 \| 12/63	150	326	489	498	316	360	402	224	260
	170	366	529	538	316	360	402	224	260
	210	446	609	618	316	360	402	224	260

Dimensions of earthing switch UWA-EL

UWA	Z	A1	A2	A3	B1	C1
12/25 \| 12/63	150	350	418	588	232	257
	170	390	458	628	232	257
	210	470	538	708	232	257
17/25 \| 17/63	180	380	450	605	262	277
	210	440	510	685	262	277
	275	570	640	795	262	277
	300	620	690	845	262	277
24/25 \| 24/63	170	390	460	640	292	312
	210	470	540	720	292	312
	275	600	670	850	292	312
	300	650	720	900	292	312

The offer of ELTOM company also includes earthing switches having a short-circuit making capacity (class E1). Devices are designed to work indoor.

Class durability of electrical earthing			UWS12/40/Z/...	UWS12/50/Z/...	UWS24/31,5/Z/...	UWS24/50/Z/...
rated voltage	Ur	kV	12	12	24	24
withstand lighting impulse voltage	Up	kV	70/85	70/85	125/145	125/145
short-time rated withstand current	Ik	kA	40	50	31,5	50
rated time of the short-circuit	tk	s	1	1	1	1
peak rated withstand current	-	kA	100	125	78	125
durability class of electrical of earthing switch	Er	-	E1	E0	E1	E0