1.Long term stability and high reliability
2.High impulse level protection
3.High accuracy load ranges
4.Easy for maintenance
Minimum Order Quantity: 300 Piece/Pieces
Supply Ability: 30000 Piece/Pieces per Month
Payment Terms: L/C,D/A,D/P,T/T,Western Union
Contact SupplierPackaging Detail: depends on destination, type of transport and specificrequirements of individual buyers.
Delivery Detail: in 25Days
The electricity meter type DD28 is suitable for measuring active energy for direct connection in single-phase, two-wire networks.
COMPLIANCE WITH STANDARDS
The measuring and technical qualities of the meter DD28 comply to International Electrotechnical Commission Publications (IEC 521), German Standard (VDE 0418)...
Their construction and mechanical dimensions comply with DIN 43857 and all respective DIN dimensional standards. Its construction enables adaptation to various requests in the measuring and technical qualities.
Meter type | DD28 | DD282 | DD283 | DD284 | ||
Reference voltage | 230 V | |||||
Special version | from 100 V to 500 V | |||||
Reference frequency | 50 Hz (special version 60 Hz) | |||||
Consumption of voltage electromagnet at 230 V, 50 Hz | 1 W 3,9 VA | |||||
Basic current (A) | 10 | 5 | 10 | 10 | 5 | 10 |
Maximum current (A) | 30 | 20 | 40 | 50 | 30 | 60 |
Thermal current 1,2 Imax (A) | 36 | 24 | 48 | 60 | 36 | 72 |
Consumption of current electromagnet at basic current | 0,18 W 0,35 VA | 0,14 W 0,33 VA | 0,18 W 0,35 VA | 0,12 W 0,23 VA | 0,12 W 0,23 VA | 0,12 W 0,23 VA |
Specific speed (r.p.m.) | 23 | 14,375 | ||||
Rated torque at Ur, Ib, fr, | from 4,00 to 4,70 x 10-4 Nm approx. | |||||
Starting current | 0,45 % Ib | |||||
No-load running | there is no no-load running from 80 % to 110 % Uref | |||||
Dielectric strength | 2000 V, 1 min. | |||||
Surge voltage strength 1,2/50 µs | > 7 kV | |||||
Rotor weight | – meters with magnetic bearings 27 g – meters with dual-cup bearing 24 g | |||||
Weight of meter | 1,3 kg |
CONSTRUCTION
Base and cover
The case comprises base and cover of moulded insulating black material (Bakelite) highly resistant to creep currents. Improved version of the meter case enables better sealing of the meter cover and the base by means of Perbonane sealing
gasket inserted in the groove of meter cover. It prevents penetra- tion of dust and humidity into
the meter interior.
Degree of protection level com- plies to IEC 529 - IP 53.
Both, the bakelite or the thermo- plastic transparent meter cover can be applied to the meter.
The meter cover is fixed to the base diagonally by two captive sealing screws.
The bakelite cover is provided with a glass window through the meter can be read and the rotor observed. The window is fixed in the cover by means of a frame held in position and
by four fixing washers and sealed by silicon material.
The transparent meter cover is made of solid, self-extinguish- able, thermoplastic material.
The hanging hook and two bores for fixing the meter are also provided on the meter base.
Terminal block
This is an integral part of the meter base and is dust proof. The brass terminals are inserted into the terminal aperture from the front side of the meter base. In addition the shutter made of solid, self-extinguishable, ther- moplastic material is screwed over the terminal after built - in them. Maximum diameter of the terminal hole is 6,5 mm or on special request 7 mm, which enable the connection of outer wires more than 25 mm2. Fixing of outer wire is provided by means of two M6 screws. Diam- eter of the auxiliary terminal hole is 3,2 mm.
The voltage circuit can be dis- connected from the current cir- cuit in two ways :
– under the terminal cover by removing the terminal link and / or
– under the main meter cover by removing the voltage coil connection from current to voltage terminal.
Terminal cover
There are two terminal covers available - short which covers only the terminal compartment and extended which extends below the meter. Both covers are sealed independently from the meter case.
Carrying frame
is made of die - cast SiAl alloy, which enables high mechanical strenght and stability during the long time operation period. The carrying frame is fixed by two self-cut thread screws to the bakelite bearer made on the moulded meter base.
Driving system
The tangentional driving element is fixed to the robust carrying frame and consists of separate voltage and current electromag- nets.
The voltage coil is wound onto a thermoplastic frame covered by PVC shrinking tube. It can be additionally insulated by polyurethane resin to give higher breakdown resistance.
The current coil is synthetic resin insulated wire formed around a thermoplastic frame and give additional insulation against the current core and the carrying frame.