Manual

P30 SLIP COMPENSATION

SLIP COMPENSATION is used to counteract changes in motor speed (slip) caused by changes in load.

In a standard AC induction motor, the shaft speed decreases as load increases, and increases as load

decreases. By increasing or decreasing the output frequency in response to an increasing or decreasing

load, the slip is counteracted and speed is maintained. Most standard NEMA B motors have a 3% slip

rating.

P31 - P37 PRESET SPEED #1 - #7

Preset speeds are activated by contact closures between TB-11 and TB-13A, 13B, and 13E. The TB-13

terminals must be programmed as preset speed selects using Parameters 10-12.

NOTE 1: Preset speeds can operate below the frequency defined by the Minimum Frequency

parameter (Parameter 23).

Refer to the table below for activation of the preset speeds using the TB-13 terminals.

NOTE 2: When a TB-13 terminal is programmed for a function other than a preset speed select, it

is considered OPEN for the table above.

Preset Speed #6 and #7 can also be used as skip frequencies to restrict the drive from operating at

frequencies that cause vibration in the system. See Parameter 38 below.

P38 SKIP BANDWIDTH

The SM Series

™

drive has two skip frequencies that can be used to lock out critical frequencies that cause

mechanical resonance in the system. Once SKIP BANDWIDTH is set to a value other than 0 Hz, the

skip frequencies are enabled. When the skip frequency function is enabled, PRESET SPEED #6 and #7

are used as the skip frequencies. SKIP BANDWIDTH sets the range above the skip frequencies that the

drive will not operate within.

SPEED # TB-13A TB-13B TB-13C

1 CLOSED OPEN OPEN

2 OPEN CLOSED OPEN

3 OPEN OPEN CLOSED

4 CLOSED CLOSED OPEN

5 CLOSED OPEN CLOSED

6 OPEN CLOSED CLOSED

7 CLOSED CLOSED CLOSED