Motor Controllers
Installation & Setup Guide
How to mount and wire the SP-3P complete three-phase smart motor starter into a motor control panel.
Section: Starter 3-Phase
Safety Requirements
The SP-3P handles live 415V AC three-phase mains on its input terminals. All mains wiring must be performed with the supply isolated, locked off, and proved dead at all three phases before any work begins.
Steps
- Isolate the incoming three-phase supply at the main switch-disconnector or MCB feeding the panel. Apply a lock-out tag-out.
- Prove dead at R, S, T terminals using a calibrated voltage tester — test R-S, S-T, and R-T before touching any wiring.
- 415V AC three-phase wiring must be performed by a qualified electrician.
- 12V DC control supply and RS485 wiring to the built-in MX-3P module may be handled by a competent technician once the mains is isolated.
- Never apply mains voltage to the 12V DC or RS485 terminals on the MX-3P module.
Tools Required
Tool Checklist
| Preview | Quantity | Item | Details |
|---|---|---|---|
| × 1 | Flat-Head Screwdriver (6 mm) | For R, S, T input and U, V, W output mains terminal screws on the SP-3P assembly | |
| × 1 | Flat-Head Screwdriver (3 mm) | For MX-3P RS485 and 12V DC control terminal screws | |
| × 1 | Wire Strippers | For preparing 4 mm² mains cable ends and 1.0 mm² control cable | |
| × 1 | Calibrated Voltage Tester | To prove dead at all three phases before work and confirm voltage after power-up | |
| As required | 4 mm² Three-Core Cable | For R, S, T supply input and U, V, W motor output connections (size to motor current) | |
| × 1 | Clamp Meter | To measure motor running current on each phase during commissioning | |
| As required | RS485 Shielded Twisted-Pair | 1.0 mm² shielded cable from MX-3P RS485 terminals to gateway |
Flat-Head Screwdriver (6 mm)
For R, S, T input and U, V, W output mains terminal screws on the SP-3P assembly
Flat-Head Screwdriver (3 mm)
For MX-3P RS485 and 12V DC control terminal screws
Wire Strippers
For preparing 4 mm² mains cable ends and 1.0 mm² control cable
Calibrated Voltage Tester
To prove dead at all three phases before work and confirm voltage after power-up
4 mm² Three-Core Cable
For R, S, T supply input and U, V, W motor output connections (size to motor current)
Clamp Meter
To measure motor running current on each phase during commissioning
RS485 Shielded Twisted-Pair
1.0 mm² shielded cable from MX-3P RS485 terminals to gateway
What's in the Box
Included Items
| Preview | Quantity | Item | Details |
|---|---|---|---|
| × 1 | SP-3P Starter Assembly | Pre-assembled three-phase contactor + overload relay + MX-3P module | |
| × 1 | RS485 Terminal Block | 2-position screw terminal for RS485 A and B wiring | |
| × 1 | 12V DC Input Terminal | 2-position terminal for 12V DC control power supply connection | |
| × 1 | Phase Sense Terminal Block | 3-position terminal for R, S, T phase sense wires (tapped from mains input) | |
| × 1 | DIN Rail Mounting Clip | Spring clip for 35 mm DIN rail — for SP-3P-9 and SP-3P-18 models | |
| × 1 | Panel Mounting Bracket | Direct panel mount bracket for SP-3P-32 model (larger contactor, back-plate mount) | |
| × 1 | Quick Installation Card | Printed terminal wiring diagram for R/S/T input, U/V/W output, RS485, and 12V DC |
SP-3P Starter Assembly
Pre-assembled three-phase contactor + overload relay + MX-3P module
RS485 Terminal Block
2-position screw terminal for RS485 A and B wiring
12V DC Input Terminal
2-position terminal for 12V DC control power supply connection
Phase Sense Terminal Block
3-position terminal for R, S, T phase sense wires (tapped from mains input)
DIN Rail Mounting Clip
Spring clip for 35 mm DIN rail — for SP-3P-9 and SP-3P-18 models
Panel Mounting Bracket
Direct panel mount bracket for SP-3P-32 model (larger contactor, back-plate mount)
Quick Installation Card
Printed terminal wiring diagram for R/S/T input, U/V/W output, RS485, and 12V DC
Removing an Old Starter
When upgrading an existing three-phase DOL starter, the SP-3P replaces the complete starter assembly. The previous contactor, overload relay, and control accessories should be removed from service instead of remaining electrically connected.
Steps
- Remove or isolate the previous DOL contactor, overload relay, timer relay, and manual control circuit before energising the SP-3P.
- Reuse only healthy incoming and outgoing power cables that match the motor current rating and local installation standards.
- Do not leave any old auxiliary coil wiring connected to the motor control path after the SP-3P is installed.
- If the existing panel has ammeters, selector switches, or status lamps that must be retained, reconnect them only after verifying their compatibility with the new SP-3P control arrangement.
- Update the panel schedule and equipment labels so maintenance personnel know the old starter has been removed and replaced by the SP-3P.
Guided Help Center
Identify the complete old three-phase DOL starter assembly and isolate it from the panel.
Assembly Mounting
SP-3P-9 and SP-3P-18 mount on a 35 mm DIN rail. SP-3P-32 mounts on the enclosure back plate using the supplied bracket. All models require ventilation clearance around the contactor.
Steps
- With mains isolated and proved dead, mount the SP-3P assembly on the DIN rail (SP-3P-9/18) or bolt to the back plate (SP-3P-32).
- Leave at least 30 mm clearance above and below the assembly for heat dissipation — three-phase contactors generate more heat than single-phase units at full load.
- Mount the 12V DC DIN rail power supply adjacent to the SP-3P assembly.
- Plan the cable routes before wiring: R/S/T input cables from the MCB/switch-disconnector; U/V/W motor cable to the motor terminal box; RS485 cable to the gateway in a separate low-voltage duct.
Guided Help Center
Select DIN rail or back-plate mounting based on the SP-3P model size.
Mains & Motor Wiring
Connect the three-phase supply to R, S, T input terminals and the motor to U, V, W output terminals on the SP-3P assembly. Cable size must match the motor FLA — use the minimum sizes specified below, or as required by the local wiring installation standard.
Steps
- Connect phase R from the MCB/switch-disconnector to SP-3P terminal R.
- Connect phase S to SP-3P terminal S.
- Connect phase T to SP-3P terminal T.
- Connect motor terminal U to SP-3P output terminal U.
- Connect motor terminal V to SP-3P output terminal V.
- Connect motor terminal W to SP-3P output terminal W.
- Connect the motor earth (PE) to the enclosure earth bar — do not connect earth through the SP-3P assembly.
- Set the overload relay FLA dial on the SP-3P front panel to the motor nameplate current (FLA). The dial is on the overload relay section of the assembly.
- Connect 12V DC V+ and V− to the MX-3P control terminals inside the SP-3P assembly.
- Connect RS485 cable: A core → MX-3P RS485-A; B core → RS485-B. Shield to earth at panel end only.
Guided Help Center
Terminate the three incoming supply phases at R, S, and T on the SP-3P.
Commissioning & First Start
Steps
- Restore 12V DC power first — confirm the MX-3P LED illuminates (green or flashing blue).
- Restore three-phase mains supply to the panel.
- Complete Gateway Linking before issuing the first start command — see the Gateway Linking guide.
- From the app, tap Manual Control → Start. The SP-3P contactor should click and the motor should start.
- Measure motor running current on all three phases (R, S, T) using a clamp meter — confirm balanced current within 5% and within ±10% of the nameplate FLA.
- If the motor runs in the wrong direction: isolate mains, then swap any two of the motor terminal connections at the motor terminal box (e.g., swap U and V). Do NOT swap supply phases at R/S/T.
- Check phase-loss detection: temporarily remove one phase sense wire and confirm the app reports a phase-loss alarm within 2–5 seconds. Reconnect and reset.