Perhaps the last mail did not go out. Regards, Ramon > -----Original Message----- > From: Dehoyos, Ramon > Sent: Wednesday, August 06, 2003 1:49 PM > To: [log in to unmask] > Subject: RE: [TN] Temp stability in Zone 3 > > Ed: > Change the Zone 4 and 5 temp to 140 and see if the problem still > persists. That would eliminate the exhaust situation. > Regards, > Ramon > > -----Original Message----- > From: Hal Winslow [SMTP:[log in to unmask]] > Sent: Wednesday, August 06, 2003 10:42 AM > To: [log in to unmask] > Subject: Re: [TN] Temp stability in Zone 3 > > Ed, > As you allude to, the exhaust may play a factor here. I would spend some > time making sure that all the "higher temp" zones are clean. If, for the > sake of argument, the exhaust flow was reduced on either Zone 4 or 5, you > might see some of the air, and thus the "energy" flow from zone 4 out > through the zone 3 exhaust, thus raising the temperature. > > Good luck, > Hal > > -----Original Message----- > From: TechNet [mailto:[log in to unmask]]On Behalf Of Ed > Popielarski > Sent: Wednesday, August 06, 2003 10:28 AM > To: [log in to unmask] > Subject: [TN] Temp stability in Zone 3 > > > Hi everyone, > > I ran into an issue that has me scratching my head (no, it's not > fleas!) My customer is having temp stability problems in Zone 3 of a BTU > VIP70 reflow oven no gas. Below are the setpoints of each zone in deg C: > > Z1T: 140 > Z1B: 140 > Z2T: 140 > Z2B: 140 > Z3T: 140 > Z3B: 140 > Z4T: 180 > Z4B: 180 > Z5T: 230 > Z5B: 230 > > All zones are holding +/- 1 deg C EXCEPT Z3T which after setpoint is > reached, climbs very slowly (about 5 deg C/hour) and Z3B at half that > rate. Once this 5 deg deviation is reached, the system alarms (as it > should). I have confirmed the solid state relays are not "leaking" > (swapped them with good zone), the computer is setting the duty cycle of > these at 0% (once setpoint has been reached) , this has been confirmed > electrically, and there are no ground faults in the heaters, convection > fans are running. BTU has offered the customer little, if any advice. > > My theory is that "stray energy" from Z4 and possibly Z5 are heating > Z3 which, possibly due to inadequate ventilation, cannot cool. I was > hoping someone in the forum might have experienced a similar issue and > would share that experience. I haven't measured the exhaust flow rate yet, > as I didn't want to chase a "ghost", but it IS running. > > It's not often I get stumped (Steve G. can attest to that!) but this > one really has me baffled. > > Regards, > > Ed Popielarski > QTA Machine > 27291 Jardines > Mission Viejo, Ca. 92692 > > Phone:949-581-6601 > Fax: 949-581-2448 > Cel: 949-337-2578 > > WWW.QTA.NET <http://www.QTA.NET> > --------------------------------------------------- > Technet Mail List provided as a free service by IPC using LISTSERV > 1.8e > To unsubscribe, send a message to [log in to unmask] with following > text in the BODY (NOT the subject field): SIGNOFF Technet > To temporarily halt or (re-start) delivery of Technet send e-mail to > [log in to unmask]: SET Technet NOMAIL or (MAIL) > To receive ONE mailing per day of all the posts: send e-mail to > [log in to unmask]: SET Technet Digest > Search the archives of previous posts at: > http://listserv.ipc.org/archives > Please visit IPC web site http://www.ipc.org/html/forum.htm for > additional information, or contact Keach Sasamori at [log in to unmask] or > 847-509-9700 ext.5315 > ----------------------------------------------------- > > > --------------------------------------------------- > Technet Mail List provided as a free service by IPC using LISTSERV 1.8e > To unsubscribe, send a message to [log in to unmask] with following text in > the BODY (NOT the subject field): SIGNOFF Technet > To temporarily halt or (re-start) delivery of Technet send e-mail to > [log in to unmask]: SET Technet NOMAIL or (MAIL) > To receive ONE mailing per day of all the posts: send e-mail to > [log in to unmask]: SET Technet Digest > Search the archives of previous posts at: http://listserv.ipc.org/archives > Please visit IPC web site http://www.ipc.org/html/forum.htm for additional > information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 > ext.5315 > ----------------------------------------------------- > --------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8e To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 -----------------------------------------------------