JONAH
23-03-2002, 05:17 PM
ok so it helps if u give ur correct email ad for ur user id code!!!then u can post!!!
ok 1st time at this so bear with me!
recenly commissioned 3.75m island site freezer case,
case=arneg s.bilbao
condensing unit=artic circle a300 75x,twin fan,both active no cycling on h/p or temp,unit 3ph 380v-430v, 50hz
ref=404a,aprox 8kg
piperun aprox 10m to plantroom,7/8 3/8 pipe service
operated=pumpdown,cpr@1.5b,ast@3mins,def@30mins or +10.c term,case temp cycling@-22.c with 2.c diff.
comp lra@34a,fla@5a.voltage 396v measured at comp terms
S/HEAT 5k @-20.c case temp
on site yesterday to a breakdown
case off on comp external overload in control panel,(designated tele 10a motor rated overload),pressures equalized,reset and monitored, comp fired up and ran fine measuring current pressure etc.checked all connections,contactor,motor rated o/load (set @10a),comp terminals,voltage balance etc.
It wasnt untill i short cycled comp on LP by reducing ast to 0 min and throttling s.s.v that the fault came to life. On restarting comp went as if locked rotor by not starting (cond fans also 3ph running)and drawing upwards of 80a before overloading.
voltage balanced,correctly wired 3ph dol y.At first i thought not balancing on off cycle increased ast but unit still tripped again intermit,my manager suggest new comp (against my judgement!)fitted last nite but was back on site at 8am this morn to reset again,have temporary fitted contactor and o/load assem and set to auto reset monitor for 2hrs no problems,had similar prob year ago but with 3hp 240v unit,where after much deliberation and comp electrics we called in meb.they found supply voltage inadequate for store.im not ruling this possibility out,but just looking for a fresh approach from other engineers. sorry so long
thanx jonah.
ok 1st time at this so bear with me!
recenly commissioned 3.75m island site freezer case,
case=arneg s.bilbao
condensing unit=artic circle a300 75x,twin fan,both active no cycling on h/p or temp,unit 3ph 380v-430v, 50hz
ref=404a,aprox 8kg
piperun aprox 10m to plantroom,7/8 3/8 pipe service
operated=pumpdown,cpr@1.5b,ast@3mins,def@30mins or +10.c term,case temp cycling@-22.c with 2.c diff.
comp lra@34a,fla@5a.voltage 396v measured at comp terms
S/HEAT 5k @-20.c case temp
on site yesterday to a breakdown
case off on comp external overload in control panel,(designated tele 10a motor rated overload),pressures equalized,reset and monitored, comp fired up and ran fine measuring current pressure etc.checked all connections,contactor,motor rated o/load (set @10a),comp terminals,voltage balance etc.
It wasnt untill i short cycled comp on LP by reducing ast to 0 min and throttling s.s.v that the fault came to life. On restarting comp went as if locked rotor by not starting (cond fans also 3ph running)and drawing upwards of 80a before overloading.
voltage balanced,correctly wired 3ph dol y.At first i thought not balancing on off cycle increased ast but unit still tripped again intermit,my manager suggest new comp (against my judgement!)fitted last nite but was back on site at 8am this morn to reset again,have temporary fitted contactor and o/load assem and set to auto reset monitor for 2hrs no problems,had similar prob year ago but with 3hp 240v unit,where after much deliberation and comp electrics we called in meb.they found supply voltage inadequate for store.im not ruling this possibility out,but just looking for a fresh approach from other engineers. sorry so long
thanx jonah.