Schneider Electric MNA01M001EN manual Rating

LXM32

MNA01M001EN, V1.01, 08.2014

3 Engineering

Rating

Di

v

t

I

t

Figure 1: Movement cycle: Profile for energy assessment

This profile with velocity (v) and motor current (I) is also used for rating the motor and the braking resistor. The deceleration segment to be considered is labeled Di.

Calculation of the energy at constant deceleration: The total inertia (Jt) must be known.

Jt with:

Jt = Jm + Jc

Jm: Motor inertia with or without holding brake

Jc: Load inertia

The energy for each deceleration segment is calculated as follows:

E

=

1

J

ω

2

=

1

J

2πni

2

2

2

60

i

t

i

t

Units: Ei in Ws (wattseconds), Jt in kgm2, ω in rad and ni in min-1.

See the technical data for the energy absorption Evar of the devices (without consideration of an internal or external braking resistor).

In the next calculation steps, only consider those segments Di, whose energy Ei exceeds the energy absorption of the device (see chapter "2.2 DC bus data"). These excess energies EDi must be diverted by means of the braking resistor (internal or external).

EDi is calculated using the following formula: EDi = Ei - Evar (in Ws)

The continuous power Pc is calculated for each machine cycle:

Common DC bus 23