bonitron M3460R, Customer Reference Manual, Page: 17 / 37

Doc.# 985001
07/21/00
“THRESHOLD VOLTAGE” AND “LOW BUS SENSE”
ADJUSTMENT PROCEDURES FOR
MODEL M3460 RIDE-THRU MODULES
1. Overview
The "Threshold" voltage level is the voltage at which the Bonitron Model M3460 Ride-Thru module
maintains the DC bus during a power dip. Whenever the DC bus level drops to the "Threshold" setpoint, the
Ride-Thru module becomes active to regulate the DC bus voltage to the "Threshold" setpoint voltage.
The "Threshold" level is factory preset on all Bonitron Model M3460 Ride-Thru modules. These levels are
specified in the General Specifications section of the Customer Reference manual for each Ride-Thru
module. However, some field adjustment of this level may be required to achieve the optimum setpoint level
for any given system.
It is important to note that the Ride-Thru module’s "Low DC Bus" or "Output Under Voltage (OUV)"
setpoint is factory preset to 25V below the "Threshold" voltage. This setpoint should be maintained at 25V
below Threshold to avoid improper OUV fault activity.
Table-1 below lists the typical factory setpoints for the "Threshold", "Low DC Bus (OUV)" and "Test Boost"
levels for the Model M3460 Ride-Thru modules based on the system AC or DC input voltage requirements.
Be sure to check the Customer Reference manual for each Ride-Thru module for specific setpoint levels.
Table-1: Factory Setpoints for Threshold and Test Boost Voltages
INPUT VOLTAGE THRESHOLD LOW DC BUS (OUV) TEST BOOST
230VAC 290VDC 265VDC +50VDC
370VDC 490VDC 465VDC +75VDC
380VAC 490VDC 465VDC +75VDC
400VAC 505VDC 480VDC +100VDC
400VDC 595VDC 570VDC +100VDC
415VAC 520VDC 495VDC +100VDC
460VAC 590VDC 565VDC +100VDC
2. Determining The Threshold Voltage Setpoint
Testing and adjustment of the "Threshold" voltage setpoint can be performed on systems in either an "On-line
and loaded" or an "Off-line and unloaded condition as described in methods 1 and 2 below. Each of the two
methods described require that you monitor the DC bus voltage during the testing and adjustment procedures.
Be sure to read through both adjustment methods completely before attempting any adjustment of the
"Threshold" and "Low DC Bus" voltage setpoints.
2.1 Method 1: Determining The Threshold Voltage Setpoint For An On-Line And
Loaded System
1) Verify proper installation.
Ensure that the Bonitron Model M3460 Ride-Thru module has been properly installed and wired according to
all applicable system and module wiring diagrams.
2) Push the "Test" button.
Push the "Test" button while monitoring the DC bus voltage.