Emerson Mentor MP User Manual

Parameter
description
protocol
Performance
Menu
4
With
Pr
4.16
set
to
1
or
3
when
in
slave
mode
Pr
5.43
=
8
(P.Slave)
has
no
effect
on
the
drive
thermal
protection.
The
current
limit
applied
at
any
time
depends
on
whether
the
drive
is
motorin
g
or
regenerating
and
also
on
the
level
of
the
symmetrical
current
limit.
See
Pr
4.16
on
page
64.
This
parameter
displays
the
current
magnitude
(Pr
4.01
{
di08,
0.43
})
as
a
percentage
of
rated
active
current.
Positive
values
indicate
motoring
and
If
this
parameter
is
set
to
one,
the
drive
calculates
a
torque
reference
from
the
motor
and
load
inertia
(Pr
3.18
)
and
the
rate
of
change
of
speed
Parameter
structure
Keypad and
format
Advanced parameter
descriptions
Serial comms
This assumes that the maximum allowed motor temperature is produced by 1.05 x Motor rated current and that  is the thermal filter of the point in the
motor that reaches its maximum allowed temperature first.  is defined by Pr 4.15. The estimated motor temperature is given by Pr 4.19 as a
percentage of maximum temperature. If Pr 4.15 has a value between 0.0 and 1.0 the thermal filter is taken as 1.0.
When the estimated temperature reaches 100 % the drive takes some action depending on the setting of Pr 4.16 . If Pr 4.16 is 0, the drive trips when
the threshold is reached. If Pr 4.16 is 1, the current limit is reduced to 100 % when the temperature is 100 %. The current limit is set back to the user
defined level when the temperature falls below 95 %.
The time for some action to be taken by the drive from cold with constant motor current is given by:
T
trip
= -(Pr 4.15 ) x ln(1 - (1.05 x Pr 5.07 { SE07, 0.28 } / Pr 4.01 { di08, 0.43 })
2
)
Alternatively the thermal filter can be calculated from the trip time with a given current from:
Pr 4.15 = -T
trip
/ ln(1 - (1.05 / Overload)
2
)
For example, if the drive should trip after supplying 150 % overload for 60 seconds then
Pr 4.15 = -60 / ln(1 - (1.05 / 1.50)
2
) = 89
Each time the rated current defined by Pr 5.07 { SE07, 0.28 } or Pr 21.07 (depending on the motor selected) is altered, the accumulator is reset to zero.
NOTE
Pr 4.18 gives the limit level that applies at any instant.
negative values indicate regenerating.
reference. The torque reference is added to the speed controller output to provide inertia compensation. This can be used in speed or torque control
applications to produce the torque required to accelerate or decelerate the load inertia.
Mentor MP Advanced User Guide 65
Issue Number: 4 www.onxcontrol.com
4.18
Overriding current limit
Coding
Bit
SP
FI
DE
Txt
VM
DP
ND
RA
NC
NV
PT
US
RW
BU
PS
1
1
1
1
1
1
Range
0 to TORQUE_PROD_CURRENT_MAX %
Update rate
Background write
4.19
Overload accumulator
Coding
Bit
SP
FI
DE
Txt
VM
DP
ND
RA
NC
NV
PT
US
RW
BU
PS
1
1
1
1
1
1
Range
0 to 100.0 %
Update rate
Background write
4.20
Percentage load
Coding
Bit
SP
FI
DE
Txt
VM
DP
ND
RA
NC
NV
PT
US
RW
BU
PS
1
1
1
1
1
1
Range
±USER_CURRENT_MAX %
Update rate
Background write
4.22
Inertia compensation enable
Coding
Bit
SP
FI
DE
Txt
VM
DP
ND
RA
NC
NV
PT
US
RW
BU
PS
1
1
1
Default
0
Update rate
Background read

Emerson Mentor MP Specifications

General

Brand	Emerson
Model	Mentor MP
Category	DC Drives
Language	English