Which wire is which

[Michael CallaghanParticipant @michaelcallaghan68621]

Hi out there. I am trying to figure out the wiring on my milling motor. The motor is a Chinese item, the serial number is. MBL-1231M-300HA-S. please find name plate attached. There are 4 wires coming from the motor. However the wiring diagram I have been able to find lists the wires in the following way.

GND-BLACK

SA-YELLOW

SB-BLUE

SC-GREEN. However apart from GND I have know idea which wire is what. Can anyone help. Thanks

[Adrian R2Participant @adrianr2]

Looks like a brushless DC motor, [Edit: maybe not DC – see later] label says there should be two separate cables:

• Cable 1 is the “mains” power and has three wires in it Red, Blue, Black one for each phase of the motor.
• Cable 2 is the “hall” effect rotor position sensor, this has its own low voltage power (Red, Black) and then three signal wires (Yellow, Blue, Green)

The four wires you are asking about appear to be from the sensor cable.

This is about the limit of my knowledge of such things.

[Michael CallaghanParticipant @michaelcallaghan68621]

Here are pictures of the wires leaving the motor. The smaller block of wires is the encoder. However the main wires I have no idea which is which 

[Adrian R2Participant @adrianr2]

As its raining here I did a Google image search of the label and threw up a few matches with the Optimum BF46 mill, there are some wiring diagrams in the manual but colours used are not (always) the same as yours so be careful.

It’s possible that the 4th wire in the power cable is an earth, some tests with a multimeter might confirm that.

What are you attempting to achieve?

 

[Martin CargillParticipant @martincargill50290]

If you google the part number it relates back to the manufacturer. From the label and the manufacturers data sheet it seems to need a 3 phase 220 volt AC power supply.

 

Martin

[noel shelleyParticipant @noelshelley55608]

The mains is a simple 3phase supply at 240v, from an inverter, U,V,and W are the 3 phases the order you wire them will dictate rotation if wrong swap any 2 wires over. It is a hefty motor at 2200W . THIS IS NOT A SINGLE PHASE MOTOR

The Hall supply is for the speed sensor and is 5V. Good luck. Noel.

[SillyOldDufferModerator @sillyoldduffer]

This is a brushless motor that normally just plugs into a compatible controller.  No need to know what the wires are.

Grok says:

Wiring Connections
Based on standard specifications for similar models (e.g., MBL-123IM-300HA), the motor has 8 wires: 3 phase wires (U, V, W) and 5 Hall sensor wires (+5V, GND, SA, SB, SC). Connect as follows to a compatible BLDC controller:

Phase Wires (Power/Commutation Lines)
These are the thick wires carrying high current. Connect to the controller’s U, V, W outputs. Order matters for rotation direction—swap any two if the motor spins backward.

Motor Wire  Color (Standard)  Controller Connection Notes
U                 Red                      U (Phase A)                Main power phase.
V                 Blue                      V (Phase B)                Main power phase.
W                Black                    W (Phase C)               Main power phase.

Hall Sensor Wires (Feedback)
These are thinner wires for position sensing. The motor requires +5V power (from controller) and ground. Hall signals (SA/SB/SC) go to the controller’s Hall inputs. Pull-up resistors (if needed) are usually in the controller.

Motor Wire  Color (Standard)  Controller Connection     Notes
+5V             Red                      +5V (Sensor Power)       Supplies 5V DC to Hall sensors (20-50mA draw).
GND           Black                    GND (Sensor Ground)    Common ground for sensors.
SA              Yellow                   Hall A (HA)                      Sensor for Phase U/A.
SB              Blue                      Hall B (HB)                      Sensor for Phase V/B.
SC             Green                    Hall C (HC)                      Sensor for Phase W/C.

• Power Supply to Controller: Connect your DC power source (e.g., 300V rectified AC220V) to the controller’s + and – terminals. Do not connect directly to the motor.
• Encoder (if present): Some “-S” variants include an encoder on top (as noted in CNC forums). If your model has additional wires (e.g., A, B, Z phases for incremental encoder), connect them to the controller’s encoder inputs separately—typically 5-24V differential signals. Check for extra pins if applicable.

Step-by-Step Wiring Guide

• Identify Wires: Inspect the motor’s cable. Phases are thicker; sensors are thinner. Use a multimeter to confirm (phases show low resistance ~0.5-2Ω between pairs; sensors show open circuit).
• Connect Phases: Solder or crimp phase wires to controller U/V/W. Insulate connections with heat shrink.
• Connect Sensors: Wire Hall sensors as per the table. Ensure +5V and GND are secure—reverse polarity can damage sensors.
• Controller Setup: Configure your drive (e.g., via software) for sensored mode, pole pairs (likely 4-7 for this size—check datasheet), and direction.
• Test: Power on at low voltage (e.g., 12V temporarily if possible). The motor should spin smoothly without cogging. If jerky, check sensor wiring. If wrong direction, swap two phase wires (e.g., U and V).
  Full Power Test: Ramp up to 300V. Monitor current and temperature.

Note the GREEN wire is not Earth!!!

Dave

[Michael CallaghanParticipant @michaelcallaghan68621]

Hi Martin. Your reply got me thinking. I cut the cable wrap right back and came across the following marked wires. V,W,U and the green/yellow earth. Would it be to wire the motor to a normal single to three phase VFD. Will it run. If the green/yellow wire I found (same thickness as V,W,U wires) is not earth what is it. Does the motor need the other thinner wires connected or will it run without and use the VFD for speed control.

[Adrian R2Participant @adrianr2]

@Noel not sure why a 3 phase would need a speed sensor?

@Dave, does your AI friend know what the 4th wire is? Google “optimum bf46 wiring diagram pdf” and look towards the end of the doc, it shows 4 wires incl. earth going to the motor power.

If it is BLDC (Don’t trust me, check for yourself) then you will need a matching controller.

 

 

[Edit, and here the hall sensor for completeness]

[IanTParticipant @iant]

GROK is all powerful Adrian.

But (like Eric Morecambe) although it can play all the right notes,  they may not neccessarily be in the right order!   🙂

 

Regards,

 

IanT

 

[Robert Atkinson 2Participant @robertatkinson2]

@Michael Callaghan

What are you connecting the motor to?
What is the motor on?

Reading between the lines it sounds like you have recently aquired a machine  with the motor fitted but no electronics.

The fact that it is fitted with a hall sensor with 3 outputs tells me that it is some kind of electronically commutated motor. It is likely be a permanent magnet motor e.g. brushless DC but it does not matter. What matters is that the motor will only work when connected to a compatible electronic drive module. The four heavy wires will be 3 phases and earth. As has been said by others a quick check with an ohm meter will sort that out.

Robert.

[Michael CallaghanParticipant @michaelcallaghan68621]

Thanks for the input chaps. I think that trying to get this motor working is a bit of a none starter. I have found a three phase 1.5hp motor that will fit so will go that way as I already have a good quality VFD.

[Michael Callaghan]

On Michael Callaghan Said:

Hi Martin. Your reply got me thinking. I cut the cable wrap right back and came across the following marked wires. V,W,U and the green/yellow earth. Would it be to wire the motor to a normal single to three phase VFD. Will it run. If the green/yellow wire I found (same thickness as V,W,U wires) is not earth what is it. Does the motor need the other thinner wires connected or will it run without and use the VFD for speed control.

Brushless DC motors are a close relative of 3-phase in so far as the rotor uses permanent magnets rather than an induced squirrel or coils. Many differences though.  Though they might try to spin, I don’t believe they work reliably or efficiently with a VFD.  Likely to damage the motor  The waveform is different, the BLDC uses Hall sensors to report position, DC PWM, not AC, etc. etc.

Apparently the maker’s controller is a MBLC-2200-300H but I can’t find anyone selling them.

Dave

 

 

[IanTParticipant @iant]

but I can’t find anyone selling them

 

You could try contacting the manufacturer Michael…

Shenzhen Honka M&E Equipment Co., Ltd. is a Hi-Tech Company is specializing research and manufacture of modern permanent magnetic motor and motor controller. Now the main products of company are permanent magnetic DC Motor and controller, REPM brushless DC Motor and controller, REPM servo motor and controller, and simplifyed CNC system. The products widely being used in machine, industry.

Address: B3 Building. Huafeng Industtrial Zone, Baoyuan Road, Baoan Area, Shenzhen, Guangdong, China

Regards,

 

IanT

[Author]

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