The DDS1531 series power meters are DIN rail three phase active electronic energy meters. They adopt many advanced technologies of research and development for the power meters, like microelectronic-techniques, specialized large-scale IC (integrated circuit), digital sampling and processing technology, SMT technique, and so on. Their technical performances of power meters completely conform to International Standards IEC 62053-21 for Class 1 three phase active energy meter. DDS1531 series power meters can directly and accurately measure the load active energy consumption in the three phase AC networks of rated frequency 50Hz or 60Hz. The DDS1531 series power meters have multiple types for option, to be suitable with the various market demands. DDS1531 series power meters have features with excellent long-term reliability, small volume, light weight, perfect appearance, easy installation, etc.

√ DDS1531 series power meters with 3 Available as 35mm DIN standard rail mounted, conforming to Standards DIN EN 50022, as well as front PANEL mounted (the center distance between two mounting holes is 63mm). Two mounted methods above are optional for users.
√ 10 pole width (modulus 12.5mm), complying with Standards JB/T7121-1993.
√ Can select the step motor impulse register of 6 digits (999999kWh) or 6+1 digits (999999.1kWh) LCD display.
√ Can select the inside far infrared data communication port and RS485 data communication port. The communication protocol complies with Standards DL/T645-1997. The other communication protocol can also be option.
√ Can select the maintenance free lithium battery inside for LCD display to read the meter while the power is cut.
√ S-connection (inlet wire from bottom and outlet wire on top) has two connection types: direct connection and CT connection for option. For CT connection, there are 27 kinds CT rates to set, after setting CT rate, we can read the meter directly, no need multiplying the CT rate.
√ The CT connection meter is 7 digits LCD display: 5+2 digits (only at CT rate is 5:5A) or 7 integers, which is depended on the setting CT rate.
√ Equipped with a polarity passive energy impulse output terminal, conforming to Standards IEC 62053-31 and DIN 43864.
√ LEDs indicate separately the power state on each phase, the energy impulse signal and data communication state.
√ Automatic detection for the load current flow direction and will be indicated by LED.
√ Measure the active energy consumption in one direction on three phase, which is not related with the load current flow direction at all, complying with Standards IEC 62053-21.
√ The short terminal cover is made with the transparent PC, to reduce the installation space and is convenient for centralized installation.

Wiring diagram -1 (Type S)
(Inlet wire from bottom, outlet wire on top)	Terminals	Note
	L1	L1 Phase line
	L2	L2 Phase line
	L3	L3 Phase line
	N	Neutral line
	7 and 8	Passive energy impulse output port

Wiring diagram -2 (Type S)
(Inlet wire from bottom, outlet wire on top)	Terminals	Note
	L1	L1 Phase line
	L2	L2 Phase line
	L3	L23Phase line
	N	No use
	7 and 8	Passive energy impulse output port

Wiring diagram -3 (Type S)
(Inlet wire from bottom, outlet wire on top)	Terminals	Note
	L1	L1 Phase line
	L2	L2 Phase line
	L3	L3 Phase line
	N	Neutral line
	7 and 8	Passive energy impulse output port
	5 and 6	RS485 communication port

Wiring diagram -4 (Type S)
(Inlet wire from bottom, outlet wire on top)	Terminals	Note
	L1	L1 Phase line
	L2	L2 Phase line
	L3	L3 Phase line
	N	No use
	7 and 8	Passive energy impulse output port
	5 and 6	RS485 communication port

Wiring diagram -5 (Type S)
	Terminals	Note	Terminals	Note
	L1	CT on Phase L1	9	L1 Phase line
	L2	CT on Phase L2	11	L2 Phase line
	L3	CT on Phase L3	13	L3 Phase line
	(Inlet wire from bottom, outlet wire on top)		N	Neutral line
	7 and 8	Passive energy impulse output port
	5 and 6	RS485 communication port
	1 and 2	CT rate setting port

Wiring diagram -6 (Type S)
	Terminals	Note	Terminals	Note
	L1	CT on Phase L1	9	L1 Phase line
	L2	No use	11	L2 Phase line
	L3	CT on Phase L3	13	L3 Phase line
	(Inlet wire from bottom, outlet wire on top)		N	No use
	7 and 8	Passive energy impulse output port
	5 and 6	RS485 communication port
	1 and 2	CT rate setting port