Motor, Resolver And Encoder Cables - Infranor Gem Drive GD1 Series Installation Manual

GD1 – Installation Guide
4.5 – MOTOR, RESOLVER AND ENCODER CABLES
Motors, resolvers and encoders are grounded via their housing.
Cable inputs must be made by means of metal connectors with collars allowing the 360° shield connection.
The resolver cable must be pair twisted and shielded (sin, cos, ref.). Motor cables MUST also be shielded and
connected over 360° at both ends as shown on the shield connection diagram
The encoder inputs A, B, C, D, Z and R require a pair twisted and shielded cable. The shield must have a "360°"
connection via metallic collars at both ends. If the shield is connected by means of a pig tail, it must be connected
at one end to the GND pin of the connector on drive side with a connection as short as possible.
Check that the voltage drop in the power supply lines of the encoder cable is complying with the technical
specifications of the encoder. The voltage drop value for a given cable is calculated as follows:
with ∆U
: voltage drop in volts
Lc : cable length in metres
I : encoder current in milliamps
S : cross section in square millimetres
Due to this voltage drop:
♦
an encoder with a large power supply voltage range should be preferred,
♦
if the encoder has got power supply SENSE feedback lines, they can be connected to the power supply
lines in order to reduce the voltage drop by the half (the SENSE feedback signal is not used in the GD1
range),
♦
if none of both solutions above can be used, the user has to supply the encoder by means of an
external power supply.
Example
The application requires an Heidenhain linear encoder supplied by 5 V +/-5% / 300 mA with 25 m cable length.
Min. power voltage: 5 V +/-5%
Such a large cross section is difficult to find, so the user can:
♦
either connect the SENSE feedback signal lines with power supply lines, while the needed wires cross
section will be the half (0.6 mm
♦
or use the same encoder type but the version which allows its power supply voltage from 3.6 V to 5.25 V /
300 mA.
Min power voltage 3.6 V
The cable of brake-equipped motors must also have their brake cables shielded, in order to be EMC compliant.
Maximum cable length:
- Resolver: ≤ 100 m
- Encoder: ≤ 25 m
- Motor: ≤ 25 m
For motor cable length > 25 m, we advise:
♦
to use the maximum cable section allowed by the connectors,
♦
to mount a reactance with an inductive value between 1 % and 3 % of the motor inductive value. The
reactance inductive value must be taken into account in the calculation of the current loops. The current
rating of the reactance must be equal to or higher than the drive rating.
The reactance must be mounted at the drive output.
Due to the use of a reactance, a shielded cable is not mandatory anymore.
A more complex sinus filter type FN510 by Schaffner may also be mounted instead of the reactance.
34
Lc[m].I[mA]
-6
∆U[V] = 40.10
. _______________
(see technical specifications)
∆Umax = 0.25 V
Min. cross section: S = 1.2 mm
2
),
∆Umax = 1.4 V
Min. cross section: S = 0.21 mm
(see section
2
]
S[mm
2
.
2
.
Part 1 – Chapter 4 – Connections
4.4.2).