No power at reader
No Power at the reader
When using a LP-1502(Red 2 Reader Board) or MR-52 S3 ( Red Single Reader Board) you may have no power at the reader port.
When the panel is set to 12 volts and you are supplying 12 volts the power output to the readers are disabled. This was a change to these boards. You will need to set the jumper to pass-through. The readers will have power once set to pass-through.
Here is a recent service bulletin from Mercury Security stating the changes.
This is an important notice for users in regards to powering readers off of the LP1502 and the Series 3 MR52.
When 12VDC is applied to power the board and if 12V is selected for reader power, the reader ports will no longer supply power. Mercury made the decision to change this on purpose because
there were concerns about the output voltage stability and effects on the output capacitor failure rates, since it wasn’t designed for this. For the newer version of the boards, the 12V regulator for the reader power output is shut down when the input voltage is ~15.5V.
IMPACTED MERCURY PRODUCTS
The following table indicates which boards this pertains to and to which revisions this change applies.
(printed on PCB)
If 24VDC is applied to a board with pass-through selected: 24VDC will be passed through to reader ports.
If 24VDC is applied to a board with 12V selected: 12VDC will be supplied to the reader ports.
If 12VDC is applied to a board with pass-through selected: 12VDC will be passed through to reader ports.
If 12VDC is applied to a board with 12V selected: 0 VDC will be supplied to the reader ports.
o This is the scenario that changed. Note that while this scenario may have allowed voltage to be supplied to the reader ports on older versions of the boards, this was never the recommended configuration and has always been documented accordingly in Mercury’s installation manuals.