Cutting-off units (UZO) are open electrotechnical products of general purpose switched directly to single-phase two- and three-wire circuit of alternating current with dead-earthed neutral. Functionally UZO are subject to circuit voltage (do not automatically break in case of voltage cutting-off) and represent two-pole automatic breakers with build-in protection against overcurrent, build-in independent current release device and control module. UZO are designed for stationary installation with fixed wiring in normal and severe operating conditions according to GOST R MEC 335-1-94.
Purpose

Protection of people from electric injury in case of purposeless touch to the elements of electrical installation under voltage due to insulation failure as well as directly to one of the current-carrying elements.

Increasing of fire safety in case of insulation, electric wiring and electrical equipment failures.

Protective cutting-off of protected circuit from continuous overvoltage in power line.

Protection of circuits of alternative current of 230V and 50Hz from overloading and shorting.

Operative switching on/off of electric circuits.
Field of application

Completion of apartment, floor, illuminating, distributing dashboards and of power switchboards installed in administrative, residential and public buildings, industrial premises, cottages, garages, summer cottages, mobile constructions, etc. as well as for protection of individual power consumers.
Standard provision

UZO are developed, prepared and go into series production according to the requirements of Quality standard ISO 9001 (GOST ISO 9001-2001), and correspond to the requirements GOST R 51327.1, GOST R 51329, NPB 243, technical specifications IZHSK. 656111.004 TU.UZO 22, covered by patent No2184413.
Features

UZO maintain capacity to work:

at voltage lowering in protected circuit to 50V;

at voltage increasing in protected circuit to 246V;

after neutral wire breaking N (for 3-wire versions);

after influence of interface voltage of 380V.
Reliability characteristics

switching endurance (on/off), cycles, not less than 4000;

mean time to failure – not less than 16000 hours;

mean lifetime – not less than 15 years.

warranty lifetime – 5 years.
Construction

Cutting-off units consist of constructively detached, mechanically joined and electrically connected elements: double-pole automatic breaker comprising a bobbin of independent current release device in one of the poles and module for protective cutting-off.

The module consists of the following elements: printed-circuit board with electronic gain circuit getting supply from the protected circuit; current sensor-transformer, gating out differential current; operation control device – button “T” (TEST).
Functional schem UZO 22



Modifications

Modifications of the device	Rated current (In), A	Rated differential cutoff current (I), A
UZO22-C-10-X-010	10	0.01
UZO22-C-10-X-030		0.03
UZO22-C-16-X-010	16	0.01
UZO22-C-16-X-030		0.03
UZO22-C-25-X-030	25	0.03
UZO22-C-32-X-030	31,5	0.03
UZO22-C-40-X-030	40	0.03
UZO22-C-40-X-100*		0.1
UZO22-C-50-X-030	50	0.03
UZO22-C-50-X-010*		0.1
UZO22-C-50-X-300*		0.3
UZO22-C-63-X-030	63	0.03
UZO22-C-63-X-100*		0.1
UZO22-C-63-X-300*		0.3

Note: all the modifications are made with protective characteristic of “B” or “C” type in the overcurrent mode and for two- and three-wire connection to the circuit. * Can be made as selective.
Technical specifications

Parameter’s name	Parameter’s value
	UZO22	UZO 22E	UZO 22C
Rated voltage, 50 Hz, Un, V	230
Power consumed without load, VA, not more than	0.3
Rated maximum switching capacity, Im, A	3000, 4500
Connecting and disconnecting capacity by differential current, I∆m, А	3000, 4500
Maximum time needed to disconnect by differential current, Tn, sec, not more than	0.04 [0.05-0.15 with sign S]
Thermal characteristic in overcurrent mode - disconnecting/connecting current,	1,13 In / 1,45 In
Electromagnetic characteristic in overcurrent mode - disconnecting/connecting current, type B - disconnecting/connecting current, type C	3 In / 5 In 5 In / 10 In
Maximum time needed to disconnect in overcurrent mode, sec, not more than	0,1
Wire cross-section, mm2	1-10	1-25
Availability of UZO operation indicator by	-	-	+
Overall dimensions, mm	58х94х65	70х90х73	72x95x75
Weight, mm	0,3		0,35
Protection degree	IP20

Operating conditions

Upper value of ambient temperature is +55 0C.

Lower value of ambient temperature is - 45 0C.

Relative humidity 98% at +250C.

Lower value of atmospheric pressure is 73 kPa (550 millimeters of mercury).
Пример схемы трехпроводного включения УЗО 22 к питающей сети

Рисунок 1

Рисунок 2

Примечание: QF3 на рисунке 1 и QF1 на рисунке 2 - устройства защитного отключения с зажимом заземления, включенные в сети электропитания TN-C-S и TN-S соответственно.
Габаритные, установочные размеры и минимальные расстояния
от устройства УЗО 22 до металлических частей щитка

	Масса устройства - не более 0,3 кг.

Габаритные, установочные размеры, масса и минимальные расстояния
от устройства УЗО 22Е до металлических частей щитка
Габаритные, установочные размеры, масса и минимальные расстояния
от устройства УЗО 22С до металлических частей щитка