Results 1 to 9 of 9
  1. 01-17-2008, 05:00 PM #1
    cxagent's Avatar
    cxagent
    cxagent is offline Professional Member
    Join Date
    Mar 2004
    Location
    Austin, Texas
    Posts
    2,041
    Post Likes

    Trane MP-503 Input question

    On a Trane MP-503 input set for binary - what is considered "open" and what is considered "closed" contacts?

    I'm in the office reveiwing drawings and the drawings say that zero volts is shown as "open contacts" and 24v is shown as "closed contacts". That is backwards from what I would expect.
    If "I have always done it this way" is a good reason to do it again, how many times do I have to do something wrong - before it becomes right?
    Reply With Quote Reply With Quote
  2. 01-17-2008, 05:08 PM #2
    MDaly
    MDaly is offline Regular Guest
    Join Date
    Dec 2007
    Posts
    112
    Post Likes
    I would think that the device puts out a 24v out looking for status. If it reads 0v the contacts are open breaking the circuit, if it reads 24v the contacts are closed completing the circuit.
    Reply With Quote Reply With Quote
  3. 01-17-2008, 09:32 PM #3
    BAS_Tech
    BAS_Tech is offline Regular Guest
    Join Date
    Jan 2008
    Posts
    10
    Post Likes
    The bop's are 24v output. This means when the output is on, your energizing the end device with 24 volts ac. The binary inputs on the other hand feed out a 5vdc that it will need to see loop back in order for it to recognize the binary input as "closed".
    Reply With Quote Reply With Quote
  4. 01-19-2008, 02:59 PM #4
    seewll's Avatar
    seewll
    seewll is offline Regular Guest
    Join Date
    Dec 2007
    Posts
    89
    Post Likes
    Quote Originally Posted by BAS_Tech View Post
    The bop's are 24v output. This means when the output is on, your energizing the end device with 24 volts ac. The binary inputs on the other hand feed out a 5vdc that it will need to see loop back in order for it to recognize the binary input as "closed".
    He is correct, Do not put 24 volts on the INPUT or you will have a bad input.
    The BO is 24 VAC to make a relay, The input needs to be a dry contact as the signal is 5v like BAS Tech said.
    Reply With Quote Reply With Quote
  5. 01-19-2008, 05:40 PM #5
    BAS_Tech
    BAS_Tech is offline Regular Guest
    Join Date
    Jan 2008
    Posts
    10
    Post Likes
    Of course I'm correct. I work for the manufacturer.
    Reply With Quote Reply With Quote
  6. 01-19-2008, 07:17 PM #6
    seewll's Avatar
    seewll
    seewll is offline Regular Guest
    Join Date
    Dec 2007
    Posts
    89
    Post Likes
    Quote Originally Posted by BAS_Tech View Post
    Of course I'm correct. I work for the manufacturer.
    What Location?
    Reply With Quote Reply With Quote
  7. 01-20-2008, 10:39 AM #7
    BAS_Tech
    BAS_Tech is offline Regular Guest
    Join Date
    Jan 2008
    Posts
    10
    Post Likes
    Chicago/West Michigan.
    Reply With Quote Reply With Quote
  8. 01-20-2008, 02:07 PM #8
    seewll's Avatar
    seewll
    seewll is offline Regular Guest
    Join Date
    Dec 2007
    Posts
    89
    Post Likes
    Quote Originally Posted by BAS_Tech View Post
    Chicago/West Michigan.
    Greensboro NC
    Reply With Quote Reply With Quote
  9. 01-21-2008, 11:47 AM #9
    cxagent's Avatar
    cxagent
    cxagent is offline Professional Member
    Join Date
    Mar 2004
    Location
    Austin, Texas
    Posts
    2,041
    Post Likes
    Thread Starter
    Quote Originally Posted by BAS_Tech View Post
    The bop's are 24v output. This means when the output is on, your energizing the end device with 24 volts ac. The binary inputs on the other hand feed out a 5vdc that it will need to see loop back in order for it to recognize the binary input as "closed".
    This is more what I would expect. I would also expect that when I measure 5volts across the input, the MP-503 will consider the contacts being monitored to be open. And when the contacts are closed, I will measure zero volts across that input.
    If "I have always done it this way" is a good reason to do it again, how many times do I have to do something wrong - before it becomes right?
    Reply With Quote Reply With Quote
« Previous Thread | Next Thread »

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Forum Rules
Contracting Business

Related Forums

Plumbing Talks | Contractor MagazineThe place where Electrical professionals meet.
HPAC Engineering