chiller problem PCV Trane Centravac

[lightyear]

Went on recent service call of a trane centravac (pcv) chiller. Found defective electromechanical timer and oil pump running continously. Replaced with new digital timer (TMR 0000181) and new block (BLK000855). Restarted system oil pump runs continously and chiller starts with no time delay. Is this normal operation with replacement timer? Has anyone else come across this same problem?

[psmurf]

first: machine must NOT start until oil pressure is at run pressure. ithink 20# for that unit. better check wiring and/or another faulty control.

2: i had on where an aux switch on starter was bad(stuck closed) and pump ran steady regardless of machine control

good luck

ps. make sure pump runs at least 2 mins. after shut down or you will be replcing a lot more than controls

[chillrdude]

Is this a single door or double door control panel,you changed out the anti-recycle timer (DL4 on a wiring diagram I have). Did you check the oil pump timer should a RLY-527 or DL2 on a print. If you have a double door it is mounted on the back of one of the doors. Sounds like your trouble is the oil pump timer, seen quite a few go bad over the years.I think on most of the old ones on a call for cooling if all safeties are ok once the unit makes oil pressure it starts, not a whole lot of prelube, then when it shuts down oil pump runs for like 7 minutes, plenty of post lube.

smurf is right about aux contact on starter will keep oil pump energized if contact welds. On these old units oil pressure should be 12-15# net, oil switch opens @ 5# and closes @ 9#.

you say chiller starts with no delay, how many times did you start it and did it start back up within the timing settings that you set on the new timer. Did you get any instructions on the retrofit to the new timer, I can get them for you if you need them.

Hope this helps

[lightyear]

Thanks for your help psmurf, chillerdude and joe at trane tech support.

Had to replace defective oil pump timer relay. Oil pump now runs normal with a 7 minute post lube cycle. The new timer works fine, once I tested it. 1. With chiller running shut off chilled water pump, flow switch opened and chiller shut down oil pump timing out. 2. restarted chilled water pump afew minutes latter. Chiller started with safety circuit closed TR3 recycle timer timing. 3. Shut down chiller at control panel (single door) oil pump started timing 7 minutes, TR3 recycle timer also timing. 4. After afew minutes tried to restart system switched to run mode oil pump runs, timer timing 30 mintues delay from original start. 5. After normally closed contacts will close again, as long as all safties are made chiller will restart and close a set of holding contacts parallel with the timer contacts.

[cam s]

I've never seen a double-door PCV control panel. CVHA's and CVHB's have them.
Also timer designations on PCV's are TR and on CVHA's and CVHB's are DL.
A CVHA may be a "Sidewinder", but it's not a PCV.