Suggested Setup Procedure For The Vsd Control – Parallel Positioning Application; Prerequisites - Siemens LMV3 series Technical Instructions

Technical Instructions
Document No. LV3-1000
Suggested Setup Procedure for the VSD Control – Parallel Positioning Application
After verifying that all VSD blower-related components are installed and wired correctly, the LMV3
control can be programmed for the VSD blower application. Naturally, this must be done before the
Ratio Control Curves are commissioned.
This procedure will cover two types of VSD. Setup of a variable frequency drive (VFD) with a three phase
motor will be covered, as well as a brushless DC (PWM) blower.

Prerequisites

For three phase motors with a VFD:
The arrow on the speed wheel must point in the same direction as the correct blower rotation.
•
The gap between the inductive speed sensor and the speed wheel finger is correct (approx. 1/16").
•
The VFD, motor, and LMV3 share a common ground.
•
The analog signal from the LMV3 to the VFD must be in shielded cable with one end of the shield
•
grounded.
The VFD is programmed correctly (see "Configuring VFDs for use with the LMV3") earlier in this
•
section for guidance.
For brushless DC blowers (PWM blowers):
Ensure that the PWM blower is a closed loop type, meaning that it is utilizing an on-board speed
•
control properly tuned for that specific blower.
Ensure that the maximum closed loop speed that the PWM blower is programmed for is adequate
•
for the application.
Ensure the wiring is correct, paying particular attention to the low voltage wiring. Some PWM
•
blowers have their electronics internally powered from the high voltage, while others require
separate, external low voltage power.
After these points are double-checked, the LMV3 parameters can be set for the application.
1. Set the VSD ramp times.
a. Ramp up = Parameter 522
b. Ramp down = Parameter 523
c. Modulation ramp = Parameter 544
These ramp times must be set at least 10% longer than the capabilities of the connected VSD. For
example, if the VSD can ramp up is 25 seconds, then parameter 522 must be set to at least 27 seconds.
The same logic applies for the ramp down, parameter 523. The modulation ramp has a minimum setting
of 32 seconds. If parameters 522 or 523 are more than 32 seconds, match the setting of parameter 544
to the longer ramp time which will be the value of 522 or 523.
Section 5 Page 20
LMV Series
SCC Inc.