A-BAdjustable Frequency AC Drive

these points must be connected to adjacent building steel (girder, joist), a 

floor ground rod or bus bar. Grounding points must comply with national 

and local industrial safety regulations and/or electrical codes.

Motor Ground

The motor ground must be connected to one of the ground terminals on 

the drive.

Shield Termination - SHLD

Either of the safety ground terminals located on the power terminal 

block provides a grounding point for the motor cable shield. The motor 

cable shield connected to one of these terminals (drive end) should also 

be connected to the motor frame (motor end). Use a shield terminating or 

EMI clamp to connect the shield to the safety ground terminal. The 

conduit box option may be used with a cable clamp for a grounding point 

for the cable shield.

When shielded cable is used for control and signal wiring, the shield 

should be grounded at the source end only, not at the drive end.

RFI Filter Grounding

Using single phase drives with integral filter, or an external filter with 

any drive rating, may result in relatively high ground leakage currents. 

Therefore, the filter must only be used in installations with grounded 

AC supply systems and be permanently installed and solidly 

grounded (bonded) to the building power distribution ground. Ensure 

that the incoming supply neutral is solidly connected (bonded) to the 

same building power distribution ground. Grounding must not rely on 

flexible cables and should not include any form of plug or socket that 

would permit inadvertent disconnection. Some local codes may require 

redundant ground connections. The integrity of all connections should be 

periodically checked

Fuses and Circuit Breakers

The PowerFlex 40 does not provide branch short circuit protection. This 

product should be installed with either input fuses or an input circuit 

breaker. National and local industrial safety regulations and/or electrical 

codes may determine additional requirements for these installations. 

Fusing

The PowerFlex 40 has been UL tested and approved for use with input 

fuses. The ratings in the table that follows are the minimum 

recommended values for use with each drive rating. The devices listed in 

this table are provided to serve as a guide.

Bulletin 140M (Self-Protected Combination Controller)/UL489 

Circuit Breakers

When using Bulletin 140M or UL489 rated circuit breakers, the 

guidelines listed below must be followed in order to meet the NEC 

requirements for branch circuit protection.

• Bulletin 140M can be used in single and group motor applications.

• Bulletin 140M can be used up stream from the drive without the 

need for fuses.

Fuses and Circuit Breakers

!

ATTENTION: To guard against personal injury and/or equipment 

damage caused by improper fusing or circuit breaker selection, use only 

the recommended line fuses/circuit breakers specified in this section.

Power Wiring

!

ATTENTION: National Codes and standards (NEC, VDE, BSI, etc.) 

and local codes outline provisions for safely installing electrical 

equipment. Installation must comply with specifications regarding wire 

types, conductor sizes, branch circuit protection and disconnect 

devices. Failure to do so may result in personal injury and/or equipment 

damage.

!

ATTENTION: To avoid a possible shock hazard caused by induced 

voltages, unused wires in the conduit must be grounded at both ends. 

For the same reason, if a drive sharing a conduit is being serviced or 

installed, all drives using this conduit should be disabled. This will help 

minimize the possible shock hazard from “cross coupled” power leads.

Motor Cable Types Acceptable for 200-600 Volt Installations

A variety of cable types are acceptable for drive installations. For many 

installations, unshielded cable is adequate, provided it can be separated 

from sensitive circuits. As an approximate guide, allow a spacing of 0.3 

meters (1 foot) for every 10 meters (32.8 feet) of length. In all cases, 

long parallel runs must be avoided. Do not use cable with an insulation 

thickness less than 15 mils (0.4 mm/0.015 in.). Do not route more than 

three sets of motor leads in a single conduit to minimize “cross talk”. If 

more than three drive/motor connections per conduit are required, 

shielded cable must be used.

UL installations in 50°C ambient must use 600V, 75°C or 90°C wire.

UL installations in 40°C ambient should use 600V, 75°C or 90°C wire.

Use copper wire only. Wire gauge requirements and recommendations 

are based on 75 degree C. Do not reduce wire gauge when using higher 

temperature wire.

Unshielded

THHN, THWN or similar wire is acceptable for drive installation in dry 

environments provided adequate free air space and/or conduit fill rates 

limits are provided. Do not use THHN or similarly coated wire in wet 

areas. Any wire chosen must have a minimum insulation thickness of 15 

mils and should not have large variations in insulation concentricity.