By Kent · Lock Depot Staff Writer

Two boards with nearly the same name and different jobs

The Securitron PDB-1R and PDB-8F2 both start with PDB, both sit in the same cabinet, and both handle power. That is where the likeness ends. One of them listens for a fire alarm and moves power in response. The other splits one supply into eight circuits. Buy the wrong one and you will not find out until the panel is on the wall and the system does not behave.

The PDB-1R: power that follows the fire alarm

The PDB-1R is a fire trigger with a relay interface board. Per the listing, it uses an end of line resistor, which the listing describes as a fire relay, to trigger a form C contact when the fire system goes into alarm. It then moves power from the Normally On output to the Normally Off output.

In plain terms: you have locks that must drop when the building alarms. The board watches the alarm signal and switches the circuit, so the locks release. The listing names the triggers it handles:

• Normally open or normally closed, with a supervised end of line resistor.
• A normally closed override switch input.
• A normally closed auxiliary switch input.
• Ground fault detection.
• Trigger status reporting.

It runs in latching or non-latching mode. Latching means it stays tripped until someone resets it. Non-latching means it recovers when the alarm clears. That is a design decision for the building and the fire alarm contractor, not for the counter. The board also reports status back to fire control or annunciation equipment, and it can supervise ground through a jumper. The listing shows the board as UL 294 and UL 603 listed and ULC-S318-96 recognized.

The PDB-8F2: one supply, eight fused circuits

The PDB-8F2 does not know a fire exists. It takes the output of a power supply and divides it into eight Class 2 power limited fused outputs, each rated 2 amps. The listing says the point is to separate equipment onto individual circuits, so each load sits on its own fused output.

• Accepts AC or DC input and gives the same type out.
• 12 or 24 volt output, set by the power supply feeding it.
• An LED shows each output, and a main LED shows input power. It can indicate AC, DC or reverse DC input.
• A separate fuse can protect the main input from surges.

How to choose

You need	Order
Locks to release when the fire alarm trips	PDB-1R
Status of that release sent to the fire panel	PDB-1R
Many doors on separate fused circuits from one supply	PDB-8F2
Both, in the same cabinet	Both boards, with a supply sized for the load

A system with a dozen maglocks usually wants both: the 8F2 to divide the load, the 1R to drop it when the alarm trips. Count the amps. Eight outputs at 2 amps is the limit of each board, and the supply has to carry the sum of what is plugged in.

The supply comes first

Neither board makes power. Pick the supply first. Our power supply guide compares the Securitron options, and the PSP-12-3 plug in supply is the small end of the line. For the locks these boards feed, see the holding force guide, and the rest of the line is on the Securitron page.

Anything tied to a fire alarm is signed off by the fire alarm contractor and the authority having jurisdiction. We tell you what the board does. Do not use our description as a substitute for their approval.

Common questions

Does the PDB-8F2 work with a fire alarm?

No. It splits one supply into eight fused outputs. The PDB-1R is the board with the fire trigger.

How much current does each PDB-8F2 output carry?

The listing says 2 amps per output, on eight Class 2 power limited fused outputs.

What does latching mean on the PDB-1R?

The board stays tripped until it is reset. In non-latching mode it recovers when the trigger clears.

Does the PDB-1R report back to the fire panel?

The listing says it provides status feedback to fire control or annunciation systems.