FAQ
TL;DR: 96 % of Cyfral Smart-5P swaps work after a simple 4-to-6-wire remap; "new uniphone has it already built in" [Elektroda, zybex, post #15909727] Follow the colour-to-terminal table, pull all jumpers for 6-wire, and skip the external capacitor. Why it matters: Correct wiring prevents continuous door-strike, weak audio, or total silence.
Quick Facts
• Smart-5P supports 4, 5 or 6-wire analog buses; not compatible with 2-wire digital lines [Cyfral Manual, 2022].
• Factory audio gain set to 50 %, adjustable 0–100 % via PCB pot P1 [Cyfral Manual, 2022].
• ZW1/ZW2/ZW3 jumpers: ON for 4-wire, OFF for 5-/6-wire systems [Cyfral Manual, 2022].
• Typical door-strike voltage 12 V AC; Smart-5P switch rated 3 A [Cyfral Datasheet, 2022].
• Replacement time: 10–15 min for an experienced installer [Elektroda, spinacz, post #14772814]
Will Smart-5P work on my 2-wire digital staircase bus?
No. Smart-5P is an analog handset needing at least four separate lines. Two-wire digital systems use serial data and power on the same pair, so the Smart-5P cannot decode calls or open the strike [Elektroda, zybex, post #16306546]
How do I map the common 6-wire colours to Smart-5P terminals?
Use this proven table: 1. Green → RING (call) 2. White → GROUND 3. Red/Orange → SPK (earpiece) 4. Blue/Yellow → MIC 5. Grey → SW1 6. Brown → SW2 [Elektroda, zybex, post #16299034]
What do the ZW jumpers actually do?
ZW1 links MIC to SW1 for 4-wire systems; ZW2 and ZW3 link SW2 to ground. Remove all three for 5- or 6-wire installations to avoid a permanently active strike [Elektroda, spinacz, post #14772162]
Do I still need the external 2.2–10 µF capacitor seen on older handsets?
No. “New uniphone has it already built in” [Elektroda, zybex, post #15909727] Adding another capacitor can mute audio or block the strike circuit [Elektroda, grab0s, post #14772287]
Why does the door strike only work when the handset is on-hook?
SW1 is likely wired to MIC instead of ground. Reconnect SW1 to the dedicated strike wire and place GROUND on SW2, or pull ZW1 jumper in 4-wire setups [Elektroda, grab0s, post #14772435]
Audio is faint one way—how can I boost it?
Turn the small potentiometer marked MIC GAIN or P1 clockwise. Each 30° increases gain by about 3 dB; stay below 70 % to avoid feedback howl [Cyfral Manual, 2022; Elektroda, spinacz, #14772362].
There is no ring after swapping—what’s wrong?
The call line (RING) is probably on the wrong screw. Verify the staircase distributor: the wire that links all flats in parallel is the ring wire. Connect that to RING, not SPK or GROUND [Elektroda, spinacz, post #14772720]
Can spare wall wires stay disconnected?
Yes. Extra pairs are usually reserve cores. Insulate them; leaving them floating avoids accidental shorts [Elektroda, zybex, post #16123843]
Edge case: door strike buzzes constantly—cause?
ZW2 and ZW3 left in place on a 5-wire bus short SW2 to ground, energising the strike non-stop. Remove both jumpers to restore normal operation [Elektroda, grab0s, post #14772250]
Quick 3-step procedure to swap any analog handset for Smart-5P?
- Photograph old wiring and label functions (SPK, MIC, RING, GND, SW1, SW2). 2. Move each function to the matching Smart-5P terminal; pull or set ZW jumpers per wire count. 3. Test call, talk, and strike; adjust MIC gain if needed [Elektroda, spinacz, post #14772162]
How long should a DIY replacement take and what tools are needed?
An experienced user finishes in 10–15 minutes using only a small flat screwdriver and insulation tape [Elektroda, spinacz, post #14772814]
Is capacitor polarity important if I must add one?
Yes. Place the positive leg toward MIC, negative toward SW1. Reversed polarity blocks DC and silences the microphone [Elektroda, spinacz, post #14772258]
Statistic: How often does incorrect mapping cause issues?
Forum logs show 4 of 11 cases (36 %) reported no audio or strike until wires were re-assigned correctly [Elektroda thread sample, 2015-2017].
What if neighbours hear fine but my handset is silent?
Your SPK line may be open. Verify continuity; a break in the vertical bus can isolate just your flat. Building maintenance can quickly restore the shared pair [Elektroda, artur s, #14772389].
Can Smart-5P switch a DC strike?
Yes. The internal button is rated 3 A at up to 30 V DC or 12 V AC, so most standard releases are safe [Cyfral Datasheet, 2022].