The power supply for a Dahua 2-wire intercom
The EDP-240-48 supplies 48 VDC and 5 A, the voltage on which the Dahua 2-wire switch operates. It clips onto a DIN rail, so it fits next to the switch in the meter cupboard.
In a 2-wire installation you do not power each device separately. The switch puts the 48 volts from this power supply onto the two wires, and the indoor stations and outdoor stations draw their power from there. One power supply in the meter cupboard therefore runs the whole intercom, including the screens in the homes and the door station outside.
Why 5 amps
How many devices a 2-wire switch can power depends on the current the power supply delivers. In the manual for the 2-wire switch, Dahua gives these limits, measured with RVV cable up to 50 metres per line:
| 48 VDC, 1.25 A | 6 indoor stations and 1 outdoor station |
| 48 VDC, 3 A | 10 indoor stations and 2 outdoor stations |
| 48 VDC, 5 A | 20 indoor stations and 2 outdoor stations |
With this power supply you are therefore at the maximum that one switch can handle. For a home with a few screens that is generous; for an apartment building or a building where stations are added later it is exactly what you need.
What it fits
The EDP-240-48 is intended for the Dahua VTNS2003B-2 2-wire switch, which requires 48 VDC with a current between 1 and 5 A. Through that switch it then powers the devices connected to the 2 wires, such as the VTH5422 indoor stations and the VTO4202F outdoor stations. The maximum distance between switch and device is 50 metres.
The switch itself can also be mounted on a DIN rail, so the power supply and switch sit side by side on the same rail. You buy a 35 mm rail separately; it is not included with either of them.
The details at a glance
| Power supply input | 100-240 VAC, 2.8 A |
| Power supply output | 48 VDC, 5 A (240 W) |
| Mounting | DIN rail |
| Application | Dahua 2-wire intercom |
| Model code | EDP-240-48 |
The full specification is in the Dahua datasheet.
Frequently asked questions
Can I also use a 24 volt power supply?
No. The 2-wire switch runs on 48 VDC and passes that voltage on to the indoor stations and outdoor stations. The system will not start on 24 volts.
Do I need the 5 amps, or is a smaller power supply enough?
That depends on the number of stations. For up to 6 indoor stations and 1 outdoor station, a 1.25 A power supply is sufficient. If you have more stations, or want to be able to expand later, this 5 A unit is the safe choice. Unsure? Let us know how many screens and outdoor stations there will be, and we will check the calculation.
Does this also power the screens and the outdoor station?
Yes. You only connect this power supply to the 2-wire switch. The switch puts the 48 volts onto the two wires, and all stations connected to them draw their power from there. Separate power supplies per screen are not needed.
Is a DIN rail included?
No. The power supply is made for a standard 35 mm rail, but that rail is not included. The same applies to the 2-wire switch.
Does this fit my model?
The models this part fits are listed in the Dahua datasheet. If you are unsure, call or email us with the model you have and we will look it up.
