Simplex 4098-9843 — epoxy-encapsulated SPDT control relay (PAM-SD), 24 VDC coil.
This is the part that lets a fire alarm panel operate something that is not a fire alarm device: HVAC shutdown, door release, elevator capture, damper control, or any other auxiliary function that needs a clean dry contact. The relay is fully encapsulated in epoxy, which is why it can live in a mechanical room or inside an air handler enclosure where an open relay would not survive.
- Form C (SPDT) contacts
- Coil input 18–32 VDC; 15 mA at 24 VDC
- Contact rating 7 A at 0.35 p.f. at 28 VDC and 120 VAC; 250 µA at 5 VDC
- Colour-coded 18 AWG (0.82 mm²) wire leads; no LED
- Rated for 100% RH condensing humidity
- UL 864 certified as Control Unit Accessory (UOXX); CSFM approved
Encapsulated construction means it is not field-repairable — it is replaced as a unit, which is normally cheaper than the labour of diagnosing an open relay in a dirty environment.
