Mentor MP Short Form Guide 57
Issue Number:  5 www.controltechniques.com
Safety Information Product information
Mechanical 
installation
Electrical 
installation
Getting started Running the motor
SMARTCARD 
operation
Advanced 
parameters
Diagnostics UL listing
4.6.3 Internal field fuses
The internal field fuses provide protection to the field controller. The fuses can rupture if 
there is a fault in the field circuit. The user should check the internal field fuses if the 
drive is tripping field loss (FdL) and the field controller is enabled.
Figure 4-5 Removing the internal field fuses
Insert a flat-head screwdriver into the groove as shown above and lever downwards to 
remove the fuse cover. Refer to section 4.6.1
Ferraz Shawmut fuses
on page 44 for fuse 
types.
4.7 Shield connections
These instructions must be followed to ensure suppression of radio-frequency emission 
and good noise immunity in the encoder circuit. It is recommended that the instructions 
for the connection of the encoder cable be followed closely and, to use the grounding 
bracket and grounding clamp supplied with the drive, to terminate the shields at the 
drive.
4.7.1 Motor cables
Use of a motor cable with an overall shield for the armature and field circuits may be 
needed if there is a critical EMC emissions requirement. Connect the shield of the motor 
cable to the ground terminal of the motor frame using a link that is as short as possible 
and not exceeding 50 mm (2 in) long. A full 360° termination of the shield to the terminal 
housing of the motor is beneficial.
4.7.2 Encoder cable
To get the best results from shielding use cable with an overall shield and separate 
shields on individual twisted pairs. Connect the cable as illustrated in Figure 4-6. 
Assemble and clamp the overall shield to the grounded metallic surfaces at the encoder 
and at the drive ends of the cable.
Isolate the power before removing the internal field fuses.