How to check voltage on a 1746-OA16 card
How to check voltage on a 1746-OA16 card
(OP)
I am having problems with some of our 1746-OA16 cards on a SLC 500 system. I am controlling solenoid valves with this card and they are 120VAC, 25 Watt each. That should put me at .20 amps per solenoid (just shy of the .25 amp rating for each point on the card).I keep having problems with some of the ppoints burning out. This being a Triac card, I am a little confused on how to check the voltage coming out to make sure the card is working properly. I can check for voltage at each point and I get no reading, even if a point is working. Can anyone tell me the proper way to check the point on this card with the volt meter?





RE: How to check voltage on a 1746-OA16 card
Look at attachment for how this is disassembled.
since you have the term block in hand check for shorts in the field terms, ohm check with 120v off.
with power back on and isolated to which solv is causing short.
last thing to do is whichever solv is creating short, disconnect the solv at other end, make sure it is not bad wiring.
the current draw is .25a @60C and .5a @30C. Is it really that hot their(60C)?
Hope this helps, stay calm and keep a clear head, you should know what the problem is in a short time.
RE: How to check voltage on a 1746-OA16 card
RE: How to check voltage on a 1746-OA16 card
RE: How to check voltage on a 1746-OA16 card
RE: How to check voltage on a 1746-OA16 card
Steve
RE: How to check voltage on a 1746-OA16 card
Thanks Steve
RE: How to check voltage on a 1746-OA16 card
Is this what your saying?
you know how to force an output on through the program?
RE: How to check voltage on a 1746-OA16 card
RE: How to check voltage on a 1746-OA16 card
Surge Suppression
Most output modules have built-in surge suppression to reduce the
effects of high-voltage transients. However, we recommend that you
use an additional suppression device if an output module is being
used to control an inductive device such as:
• relays
• motor starters
• solenoids
• motors
Additional suppression is especially important if your inductive
device is in series with or parallel to a hard contact such as:
• pushbuttons
• selector switches
By adding a suppression device directly across the coil of an
inductive device, you will reduce the effects of voltage transients
caused by interrupting the current to that inductive device and
prolong the life of the switch contacts. The diagram below shows an
output module with a suppression device.
If you connect an SLC 500 controller triac output to control an
inductive load, we recommend that you use varistors to suppress
noise. Choose a varistor that is appropriate for the application. The
surge suppressors we recommend for triac outputs when switching
120V ac inductive loads are a Harris MOV, part number V220
MA2A, or an Allen-Bradley MOV, Catalog Number 599-K04 or
599-KA04, Series C or later.
RE: How to check voltage on a 1746-OA16 card