Cutler-Hammer - Eaton Canada

AF93/IS903 Parameter Descriptions
USING THE PARAMETERS
Remote Function (Cont.)
ÒANALOG LOAD LIMÓ - This function combines
a speed follower with an external method of
controlling the load limit:
Speed Follower - 4-20 mA connected to terminals
1 and 2. A 0-5 VDC signal can also be connected
to these terminals if the output impedance of the
transducer is less than or equal to 250 ½ and it
can output 20 mA.
Load Limit Control - 0-10 VDC, connect it to
terminals 2 and 3. Connect potentiometer to
terminals 2, 3, and 4.
This function allows you to control the load limit
and speed from a remote station in situations
where you expect wide variations in the load.
Note that ÒANALOG LOAD LIMÓ is capped by
ÒLOAD LIMITÓ (parameter 22).
Remember, when the load limit you set is
exceeded, the drive will go into foldback and
reduce speed to try to prevent further overload.
The lower you set the load limit, the lower the
speed will be when the drive goes into foldback.
If the load limit control does not prevent an
overload, the drive will shut down.
ÒDIGITAL POTÓ - This function sets up a
ÒpotentiometerÓ that allows you to smoothly
increase or decrease motor speed at a remote
station.
If you connect terminals 13 and 7, the speed
increases at the rate established by Accel Time
(parameter 11) or Accel Time 2 (parameter 14).
When you disconnect terminal 13 from 7, the
speed stops increasing and remains constant
(drive ignores terminal 11, Jog).
If you connect terminals 14 and 7, the speed
decreases at the rate established by Decel Time
(parameter 12) or Decel Time 2 (parameter 15).
When you disconnect terminal 14 from 7, the
speed stops decreasing and remains constant
(drive ignores terminal 11, Jog).
If both 13 and 14 are connected to 7 the speed
decreases at a rate established by the
appropriate deceleration time.
AF93/IS903 Instruction Manual
4-20
The POT WPR (terminal 3) is used to set the
load limit while in DIGITAL POT mode. If a load
limit control potentiometer is not used to control
torque, a jumper must be installed between
terminals 3 and 4.
Priority Interaction in REMOTE Mode
There is a priority scheme that the drive uses to
establish the speed setpoint in the REMOTE
mode:
Priority 1 (Lowest Priority) - 0-10 VDC Speed
Follower
Priority 2 - 4-20 mA Speed Follower (If Signal
exceeds 1 mA)
Priority 3 - PI Regulator
Priority 4 - Terminals 12, 13, or 14 closed to
terminal 7 (Preset Speeds or Digital
Potentiometer)
¥ If you use SPEED FOLLOWER, a current
source greater than 1 mA will override a
voltage source.
¥ If you use SPEED FOLLOWER, a voltage
source will override a current source less
than 1 mA.
¥ If you connect terminal 12, 13, or 14 to
terminal 7, Preset Speeds will override
SPEED FOLLOWER.
¥ If you use PI REGULATOR, Preset Speeds
will override the speed established by PI
REGULATOR.
¥ If you use ANALOG LOAD LIM, Preset
Speeds will override the speed follower
connected to terminals 1 and 2.
¥ You cannot override speed set by DIGITAL
POT, except by load limit.
¥ The load limit you set (using parameter 22 or
23) will fold back the speed setpoint when the
load limit is exceeded.