FieldBench
Wiring

iComfort variable AC

I+ / I−

I+ / I−

Lennox EL18XCV / SL28XCV. iComfort S30/S40 on I+ and I−. EL18XC1 is Y1/Y2 two-stage — different diagram.

Written circuit description only — FieldBench does not redraw maker schematics. Example: R to W closes on a heat call; verify 24V at W1 before you change the IFC.

Open manufacturer PDF

iComfort communicating

S30 / S40 / communicating indoor on I+ I−.

iComfort S30 / S40

R, C, I+, I−. I+ / I− are data.

  • R24V hot24V
  • C24V common24V
  • I+iComfort dataData
  • I−iComfort dataData

Communicating indoor

Same I+ / I−. A 24V Merit indoor is the other landing.

  • I+DataData
  • I−DataData
  • R24V24V
  • CCommon24V

Variable outdoor

Communicating outdoor. No dual cap.

  • I+DataData
  • I−DataData

Outdoor line — inverter drive

208/230 into the drive. No contactor slam. DC bus can stay live after the disconnect.

  • L1Line to the driveLine
  • L2Line to the driveLine
  • GNDEquipment groundLine

Landing

  • DataStat I+/I−indoor I+/I−outdoor

    iComfort data. Not Y.

  • 24VR and C at the stat

    ~24 VAC

  • LineL1 / L2outdoor

    208/230

Prove it

  • iComfort alerts first. Outdoor on the equipment list.
  • I+ / I− landing and polarity. R and C still required at the stat.

Do not

  • Do not use this on EL18XC1 or EL16XC1 / ML14XC1.
  • Do not land Y on I+.

I+ / I− are the published iComfort communicating terminals.

Plates on this landing