Page 48
IronHorse GSD8 DC Drives User Manual – 1st Ed. Rev. A – 10/15/2019
Application Examples
SCADA-driven Pump Controller with 4-20mA I/O, plus”Fault” and “Run” Relay Outputs
Description:
A GSD8 drive (with GSDA-AI-A8 installed) operating a waste pump control receives a target speed
setting from the SCADA system, 4-20 mA output. The GSD8 drive will display the actual pump rate in
liters per minute, and will continuously report the pump’s actual flow rate to the SCADA system using
the GSDA-AI-A8’s 4-20 mA output. The display will indicate in the format “xxx.x” (LPM).
The system features a visual alarm (Annunciator) and dry relay contact output to warn the operator
if any of the following “Fault” conditons have occurred: Actual or Target speed is outside specified
limits, the waste flow has stopped, the GSD8 is at maximum output, or the 4-20 mA input signal has
dropped below about 3mA (loop broken). Additionally, the “Fault” alarm will not activate if the Target
speed is zero, the “Inhibit” input is active, or an accel/decel ramp is in progress. The alarm cannot be
silenced but will reset automatically when flow rates have returned to normal.
Additionally, the system will provide a “Run” signal (as a dry relay contact) back to the SCADA to signal
that the pump is running (or not, as commanded by the SCADA).
Motor, Pump and Flowmeter Specifications and Alarm Limits:
•
Pump Output: 9.5 shaft rotations/liter
•
Flow Transducer: 73 pulses/liter
•
Desired Min. Flow Rate: 20 liters/minute, Max: 150 liters/minute
•
Alarm Min.10 liters/minute, Max: 180 liters/minute
•
Accel Rate: 100 liters/minute, Decel Rate: 50 liters/minute
•
SCADA 4-20 mA scaling (both input and output): 4mA = zero LPM, 20mA = 200 LPM
Application Diagram:
Tach
Valu
Auto
Alm2
Man
Error
---
ENTER
Parm
Alm1
Pump Specs:
19 Shaft Rotations = 2 Liters
Pump
Fluid
Outlet
Fluid
Inlet
Flow Transducer
(73 Pulses per Liter)
DC Motor
plus
123.0
“FAULT”
CONTACT
“RUN”
CONTACT
SCADA
SYSTEM
VISUAL
“FAULT”
INDICATOR
