BAFANG M420 User manual

1
DEALER MANUAL FOR MOTOR
BF-DM-C-MM G332-EN October 2019
6.1 Introduction 
6.2 Specifications 3
6.2.1 Outline and geometric size 3
6.2.2 Surface 4
6.2.3 Storage Information 4
6.3 Drive Unit Installation 5
6.3.1 List of Tools to be used 5
6.3.2 Motor Installation 5
6.3.3 Cabling 6
6.3.4 Motor Cover Installation 9
6.3.5 Chain Wheel Installation 9
6.3.6 Crank Installation 10
6.3.7 External Speed Sensor Installation 11
6.4 Maintenance 12
CONTENT
6 DEALER MANUAL FOR M420
(MM G332.250/350.C/CCB)

2BF-DM-C-MM G332-EN October 2019
6.1 INTRODUCTION
•Product Model
MM G332.250.C
MM G332.350.C
MM G332.250.CCB
MM G332.350.CCB
•Scope
Applies only to electrically powered pedelecs
developed or licensed by Bafang. It is suitable
for city and trekking bikes, which have been
developed for road use. The engine is not
suitable for sport competitions.
•Identification
The following graphic, is the identification
numbers of the product, which are shown on
the housing:
Note: Content in the label is important informa-
tion about this product. Please do not remove
the information from the motor.

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DEALER MANUAL FOR MOTOR
BF-DM-C-MM G332-EN October 2019
6.2 SPECIFICATIONS
①Motor model: MM G332.250.C / MM G332.250.CCB
Rated power (W) 250
Rated voltage (V) 36 / 43 / 48
Waterproof IP65
Certification CE / ROHS / EN14766
Outdoor Temperatures -20℃~45℃
②Motor model: MM G332.350.C / MM G332.350.CCB
Rated power (W) 350
Rated voltage (V) 36 / 43 / 48
Waterproof IP65
Certification CE / ROHS / EN14766
Outdoor Temperatures -20℃~45℃
6.2.1 Outline and geometric size

4BF-DM-C-MM G332-EN October 2019
Chain line(CL): 45/48/49mm
Shaft standard: BAFANG
6.2.2 Surface
Shockproof black coating
6.2.3 Storage Information
The pedelec should be stored in a ventilated dry room. Avoid storing the pedelec near strong magnetic
objects.

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DEALER MANUAL FOR MOTOR
BF-DM-C-MM G332-EN October 2019
6.3 DRIVE UNIT INSTALLATION
6.3.1 List of Tools to be used
Do not use impact wrenches.
Use of the Tools Tools
To tighten/loosen the screw onto the frame adapter and
the drive unit.
To tighten/loosen screws on the crank.
Internal hex wrench
To tighten/loosen screws on the motor cover. Cross screwdriver
To tighten/loosen the locking nut on the chain ring. Special tools
To tighten/loosen nuts on the frame adapter and the drive
unit. Socket spanner
6.3.2 Motor Installation
M8 Special bolts
M8 Flat washer-A
M8 Locknuts
Standard tool
A
C
B
D
1) Align the three mounting holes in the drive unit, with the mounting holes in the bike frame. From the
right side of the bike frame, insert three special M8 bolts through the frame and motor to keep the motor
in place.
2) Now from the left side of the Bike, place the washer over the bolts, and using three M8 Locking nuts
(13*13) tighten the bolts to secure the motor to the frame.

6BF-DM-C-MM G332-EN October 2019
The size of the standard tool for our company: outer diameter 17.7 and length 63. Tightening torque
requirment: 35 N.m.
Please pay attention to the direction of the cables coming out of the frame and from the motor. Please note that
the cables should not be squashed when the motor is attached to the frame.
6.3.3 Cabling
Please note: all cables can only be connected to its corresponding counterpart. Each connector is different so
there is no possibility to get the cables mixed up, all cables can only fit into one connector.
6.3.3.1 Connection of the battery cables to the motor
The female connector
(negative) from the motor
The male connector (positive)
from the motor
The male connector (negative)
from the battery
The female connector (positive)
from the battery
A
a
B
b
Please connect the negative connectors from the motor and battery together.
Please connect the positive connectors from the motor and battery together.
6.3.3.2 Connection of the EB-BUS to the motor
The male connector from
the motor
The female connector from
the EB-BUS cable
A
a
Please connect the connectors from the motor and EB-BUS cable together.

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DEALER MANUAL FOR MOTOR
BF-DM-C-MM G332-EN October 2019
6.3.3.3 Connection of the gear sensor to the motor
The male connector from the
motor
The female connector from the
gear sensor
A
a
Please connect the connectors from the motor and the gear sensor together.
6.3.3.4 Connection of the speed sensor to the motor
The female connector from
the motor
The male connector from the
speed sensor
A
a
Please connect the connectors from the motor and the speed sensor together.
6.3.3.5 Connection of the communication to the motor
The female connector from
the battery BMS
The male connector from the
motor
A
a
Please connect the connectors from the motor and the battery BMS together.

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6.3.3.6 Connection of the headlight cable to the motor
The male connector from the
motor
The female connector from
the headlight cable
A
a
Please connect the connectors from the motor and the headlight cable together.
6.3.3.7 Connection of the taillight cable to the motor
The female connector from
the motor
The male connector from the
taillight cable
A
a
Please connect the connectors from the motor and the taillight cable together.
6.3.3.8 Cable Route
Please arrange the cable connectors neatly without being squashed, so the motor cover can be secured
in place with ease.

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DEALER MANUAL FOR MOTOR
BF-DM-C-MM G332-EN October 2019
6.3.4 Motor Cover Installation
M4*8 Cross countersunk head
screws
Motor cover
A
B
As shown in the figure above, three M4*8 countersunk head screws are used to secure the motor cover
on the motor. The covers purpose is to protect and hide the cables and connectors.
Locking torque requirement :1.5N.m.
6.3.5 Chain Wheel Installation
Chain wheel
Lock nut
Special tool
A
B
C
Place the chain wheel onto the axel of the drive unit ensuring the inner teeth on the chainwheel fit cor-
rectly onto the bracket on the axel.
Using the special tool provided, tighten the locking nut onto the axel.
Torque requirement: 35 N.m.

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6.3.6 Crank Installation
Left crank
Right crank
Crank attachment screws
Crank tightening screws
M6*20
A
B
C
D
Mount the right crank on the right side of the axel, using a hex key tighten screw (C) onto the axel
(torque requirement is 1.5N.m) , this ensures the crank stays attached.Now using a Hex key tighten two
M6 * 20 (D) screws on the crank itself ensuring the crank is kept in place and cannot rotate around the
axel (torque requirement is 15N.m).
Note: Now carry out the same actions on the left side of the pedelec, ensuring the crank stays parallel to
the right crank.

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DEALER MANUAL FOR MOTOR
BF-DM-C-MM G332-EN October 2019
6.3.7 External Speed Sensor Installation
Speed sensor
Magnet for the speed sensor
A
B
Fasten the mounting screws through the speed sensor and with a cross screwdriver. Tightening the
speed sensor onto the frame. Then place the rubber seal on the speed sensor hiding the screw. Torque
requirement: 1.5-2 N.m.
(Note: Please make sure the gap between the speed sensor and the magnetic unit is between 10 and 20
mm. When the magnet is not the correct distance, this can cause Error 21)
Now place the magnet on the spoke of the wheel ensuring it is aligned to the middle of the speed
sensor. And with a star key tighten the magnet in place. Torque requirement: 1.5-2 N.m.

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6.4 MAINTENANCE
• Maintenance must be carried out by autho-
rized personnel with the correct equipment.
• Do not disassemble the motor.
• Do not use thinners or other solvents to
clean the components. Such substances can
damage the surfaces.
• Avoid water submerging, to keep the com-
ponents protected.
• Avoid using high-pressure cleaning jets.
• For prolonged storage, turn off the battery
and avoid storing near heat sources.