This metering unit is for outdoor installation, in power distribution system upto 12kV(U_m) for metering and measuring, with a factory-assembled three-phase combined transformer of CT, VT inside. Three-phase voltage transformers’ wiring method Y-Y star connection, and current transformer is optional, eg. two-phase CT, three-phase CT. Panel type is metal-clad, made from galvanized steel, stainless steel, or alloy aluminum. Enclosure surface is painted with color and protection layer for resistance to acid and alkali corrosion, and UV radiation. It is applied to connecting outdoor underground cable with utility company power system. The metering unit has two compartments, including a factory-assembled low voltage compartment for energy meter, and test terminal block of combined transformers. End customers can install a suitable energy meter in the compartment.

1.3 Electrical data

No.	item	units	specification
	Highest voltage for equipment Um (r.m.s.)	kV	12
	rated frequency	Hz	50, 60 or 50/60
	Rated lightning impulse withstand voltage (peak)	kV	75 kV, 95 kV
	Rated power-frequency withstand voltage on primary	kV	28
	Rated power-frequency withstand voltage on secondary	kV	3
	Number of CTs and VTs	pcs	3VT+3CT or 2CT+3VT
	Standard	/	IEC 61869-1:2007 \| IEC 61869-2:2012 IEC 61869-3:2011 \| IEC 61869-4:2013

II. Application

Pad mounted primary metering unit can meet the latest standards nationally and globally. It is connected with power distribution net three-phase cable for power metering management and automation system, to get primary metering more accurately. Thus, utility company will account power loss more effectively and increase revenue.

III. Features

1. Enclosure is house-shaped design, including medium voltage compartment of combined instrument transformer and low voltage compartment of energy meter. Compact design is as far as possible without affecting the greening and landscape. Outdoor pad mounted design is convenient and fast;
2. Metering unit has factory-assembled two compartments for medium voltage and low voltage, door opening sensor for safety operation, lock sealable for anti-theft electricity and unwanted open;
3. Enclosure made from stainless steel or equivalent material, such as low carbon steel. Hermetically sealed design is waterproof. Enclosure surface coating power is anti-corrosion layer, for resistance to acid and alkali corrosion, and UV radiation;
4. Touch-proof type, medium voltage combined transformer is encapsulated in casting epoxy resin with a metallic coating. No need insulation between combined transformer and compartment. This compact design vessel only needs 1/2 space compared with air insulated metering unit. No oil and no need maintenance, safety operation and environmentally friendly;
5. Primary side bushing connected through set of separable Tee connector, which meets IEC 50810/IEC 50181 interface C, or A, B.

IV. Technical data

Current transformer specifications

No	Item	specification
	Rated primary current	5A up to 600A
	Rated secondary current	5A, 1A
	Rated Continuous Thermal Current	120%, 125%, 150%, 200% etc.
	Rated Short time current (Ith) (thermal 1 second)	80xIpr, 100xIpr
	Rated Dynamic Current (Idyn)	2.5xIth
	Rated Output(VA)	12.5, 15,20
	Accuracy Class	0.2S, 0.2, 0.5S, 0.5, 1 metering
	Instrument Security Factor (FS)	5, 10
	Applicable Standard	IEC: 61869-1&2

Voltage transformer specifications

No	Item	specification
	Rated primary voltage(V)	10000/√3, 11000/√3
	Rated secondary voltage(V)	100/√3, 110/√3
	Rated Voltage Factor	1.2/Continuous 1.5/30s, 1.9/30s, 1.9/8h
	Standard connection	Y-Y (star connection)
	Rated Output(VA)	15, 20, 25, 30, 50, 75
	Accuracy Class	0.2, 0.5, 1, 3 metering
	Thermal burden(VA)	300, 400
	Applicable Standard	IEC: 61869-1&3