Soft Start issues

best49erfan

Member
Join Date
Aug 2003
Location
Titusville FL
Posts
70
I have an Allen Bradley 150-C16NBR that I have wired as below:
L1----SS-----T1
L2----SS-----T2
L3----SS-----T3


+24-----------A1
|
---------[On SW]----------IN1
|-----IN2
Note: IN2 is after the On SW

COM----------A2



This is how it shows to do it for 2 wire control in the manual. When the On SW is closed, the motor starts up and then shuts back down with no faults. It keeps repeating this until you turn the switch off.


Any ideas on what the problem could be?
 
Last edited:
Have you checked that your IN1 and IN2 are correct? Should IN2 be before the On SW for 2 wire? I don't know, I haven't seen the diagram, but it's worth looking at.
 
Post some more details about your settings and the motor, is this new or a replacement? Those are considered “smart” as is every device outside of on/off nowadays right! What are the rotarys set to?

There are LED’s on the unit. What is the status when starting? In 1 and in 2 should be high for 2 wire control which seems to be what you outlined. Did you measure the voltage across those terminals when you give the start command ?
 
It sounds like it looking or a bypass contactor to pull in
some models have a built in bypass and other require an external bypass contactor
you need to verify exactly what you have and what you need
 
Post some more details about your settings and the motor, is this new or a replacement? Those are considered “smart” as is every device outside of on/off nowadays right! What are the rotarys set to?

There are LED’s on the unit. What is the status when starting? In 1 and in 2 should be high for 2 wire control which seems to be what you outlined. Did you measure the voltage across those terminals when you give the start command ?


This is going to be a retrofit to replace a normal contactor to help prolong the life of V belts.

The motor is .3 HP. I do not believe it requires high starting torque.


I was going to post a link to the manual, but I cannot find the one that is included in the box online.
The LED stays solid green.


Settings
Soft Start
Initial torque 35%
Start time 2 sec
Kick start off
Soft stop off
Aux 1 normal
Phase rotation enable
Trip class 10
overload reset manual
Line Connection


The voltage on T1, 2, and 3 increase and then drops to zero and then starts to increase.
 
Last edited:
It sounds like it looking or a bypass contactor to pull in
some models have a built in bypass and other require an external bypass contactor
you need to verify exactly what you have and what you need


According to the manual, it does not need an external bypass contactor.
 
Actually without having the exact part number and motor size, we have no way of knowing
Some models have no bypass contractor at all, others have an internal bypass contractor and still others require an external bypass contractor.
the internal bypass contractor may not be pulling in I would start looking their first
if it's a large motor then their is a bypass
 
GaryS, in the first post the OP said it was a 150-C16NBR and in post 6 it was stated that the motor is 0.3HP but no voltages or currents were given.

best49erfan, can yo post the part number of the manual you are using it should be on the last page down the bottom, then we can look it up, or take a picture of the wiring diagram you are using.

Alan
 
Put your black lead on A2 for reference then check A1, In1, and In2 to see where you are losing your signal then go from there. Is there any programming to it for 2 wire or 3 wire?
 
it's clear we are not getting all the information here
0.3HP would never need a soft start I don't see how it would even work
it would draw less than 1 amp on start up my thinking he missed a zero or 2
30HP maybe more likely 300HP even a 30HP motor would not need a soft start unless their is some special reason for it.
and as I said before from the description it looks like the soft start is ramping up to full speed and expecting the bypass to pull in but it's not . it may be that it's just not getting the feedback from the contactor to know it pulled in. Most soft starts have a bypass otherwise you would have heat build up across the SCR's that need to be dissipated
 
GaryS, in the first post the OP said it was a 150-C16NBR and in post 6 it was stated that the motor is 0.3HP but no voltages or currents were given.

best49erfan, can yo post the part number of the manual you are using it should be on the last page down the bottom, then we can look it up, or take a picture of the wiring diagram you are using.

Alan


Yes, this motor does not need a soft start, however, it is the one that is on our PLC training station. motor is 480 VAC current is .66 FLA.
 

Similar Topics

Does a solid state soft starter have a DC Buss / DC Buss voltage like a VFD does?
Replies
1
Views
240
Haven't done much with soft starts, more-so VFDs' in my time. Looking at replacing 3 x 37KW (415 V 50 Hz) star-delta starters with soft starters...
Replies
11
Views
2,825
Is there a way to get the fault history from a SIRIUS 3RW4456 Soft Start through the HMI keypad? I've been through the manual but it is pretty...
Replies
0
Views
735
We are going to be using a SIRUS 3RW5545 Soft Start to control a 480V, 150HP fan. Looking for some recommendations for parameters to use with this...
Replies
0
Views
835
Good Morning , We have a 100 HP , 480 V (Full Load Amps 124 ) Hammer Mill motor that has a Wye/Delta starting procedure. I would like to put...
Replies
16
Views
4,163
Back
Top Bottom