×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

problems with a 230ton york air cooled screw

problems with a 230ton york air cooled screw

problems with a 230ton york air cooled screw

(OP)
I’m having problems with a YORK 230 ton air cooled screw machine.
    M/N:YCAS0230EC46YFASB
    Year:97
Roughly, for the past year, once every three months, it trips out ckt#2 with this fault message: “High DSCH Temp”. Now it is appearing more frequently.  
According to troubleshooting guide in the maintenance manual, there are three things to look at: 1. Superheat is too high
             2. Blocked air flow
             3. Faulty sensor
We have checked all three areas, and they are all with in range
1. The superheat is normally 10-12 and 10-12 on the economizer
2. The condenser coils are clean as a whistle, with all 10 motors running properly
3. The sensors are on the money
We have tried other remedies:
1. Replacing the eprom on the processing board
            2. Replacing the compressor’s  oil filter
    3. Adjusting the charge (removing gas, then adding gas)
            4. The factory even came out and looked at it and they could not fix the problem.

This machine is one of three chillers all tied together to cool this facility


This is a link to the IOM
http://www.york.com/products/esg/ServiceLit/ywpubs/201.19-NM1.pdf

Can you give me any ideas of what we can do?

RE: problems with a 230ton york air cooled screw

First, I'm not a HVAC guy but this seem to be an electrical troubleshooting problem.  I would suspect an intermittant in the discharge temperature sensor/wiring/electrical interface.  A momentary glitch here would cause the fault to be asserted.  I'd first check the temperature at the discharge outlet with a temperature meter.  You should also check that reading against the other two units to see if the temperature is indeed too hot.  The manual said 127 deg C but this is probably the internal temperature. If the temperature appears to be OK i'd first check all the wiring and connectors in the discharge temperature string.

RE: problems with a 230ton york air cooled screw

Have you ck the ground wire for good ground on the sensor

RE: problems with a 230ton york air cooled screw

(OP)
last 6 history logs
                    1    2    3    4    5    6
                    Wed.    Wed.    Tues,    Thrus.    Thrus.    Thrus.
                  May 26    May 26    May 20    May 20    May 20   May 20
                 12:47pm    12:01pm    2:11pm    2:14pm    2:09pm    1:47pm
                             
Shutdown Fault                             
System #1    No Fault    
System #2    High DSCH Temp.    
                              
Leaving Water Temp    44.5    42.9    44.9    47    43.2    42.9
Return Water Temp    47    45    47.9    48.3    45    44.7
Delta Temp            2.5    2.1    3    1.3    2.8    1.8
Ambient Air          93.6    91.3    93.1    91.8    91    91
Lead Sys.           2    2    2    2    2    2
                         
                    
Comp. #2    on    on    on    on    on    on
Run time     43 min    4 hrs. 17 min    6 hrs. 46 min    2 ins    19 min    3 hrs. 6 min.
FLA    56%    56%    57%    56%    56%    55%
                              
Oil Pres.    220    216    221    220    214    211
Suction Pres.    66    64    68    67    64    63
Discharge Pres.    244    240    245    243    236    234
                              
Oil Temp.    186    181    183    186    184    185
Suction Temp.    46    44    47    47    44    44
Discharge Temp.    260.3    260.2    260.1    260.3    260.2    260
                              
Sat. Suct Temp.    38.6    36.9    39.8    39.2    36.9    36.5
Suct Superheat    8    7.8    7.6    8.4    7.3    7.5
Sat. Disc Temp.    115.4    114.3    115.8    115.2    113.7    112.5
Disc Superheat    144.7    145.8    144.5    145    146.5    147.6
                              
Slide Valve Step 48    12    75    75    14    18
Economizer    off    off    off    off    off    off
# of Fans    2    2    2    2    2    2

RE: problems with a 230ton york air cooled screw

Well the log says the discharge temperature is at the limit.  The question is, is it true?  I still recomend you measure the discrarge temperature especially comparing it to the other running units.

RE: problems with a 230ton york air cooled screw

Did you get an answer to your problem?  Shouldn't the economiser be energised at this loading stage?  

RE: problems with a 230ton york air cooled screw

It sounds like all the cond fans are running in reverse rotation are they 3 phase? If so reverse and 2 of 3 leads

RE: problems with a 230ton york air cooled screw

(OP)
we fixed the problem.
the hydraulic 3 way valve ,which loads and unloads the compressor,was sticking.
 we replace part and the machine is now running properly

RE: problems with a 230ton york air cooled screw

Way to go Joey and thanks for letting us know the soution

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources