UT2SeanWhite
06-06-2012, 06:58 PM
Hey, I'm new to the forum and i need some dire help. I have two Carrier Supra 750 MT units down and I have to trouble-shoot and try to repair them. I'm not too sure how exactly to troubleshoot these machines. I'm an HVAC technician in the Navy and im currently doing a tour in Afghanistan, but i have a time limit to get these up or at least one of them up before i get pulled out to another location. Here are some of the problems that i am currently experiencing;
The units are using shore power as their source and i find that the units are rated for 230v, 60 hz, 3 phase. The units are powered from a generator to a "spider box" then to the reefer units. The volts that i picked up from the unit is 205. I understand that having low voltage can cause a lot of malfunctions? There have been a bunch of the little black display screens that have gone bad and i believe that its an electronic issue, but has to deal with the electricity being fed to the reefer unit. I just dont understand why so many of the display screens have gone bad. Another thing that goes bad or that i get an error code is ALT AUX, which i know now is the alternator. Here's the catch. With the unit, it will work fine half the time on shore power(randomly cuts off when its been running for an hour or two and gives an alarm). I have switched to "road" and it wouldnt start up on road or on shore power for an entire evening, but when i tried to get it working in the morning the next day, it didnt work until the second time i tried to turn it on even later in the morning. I hear a lot of clicking and buzzing from inside the micro processor box and i noticed that one of the little black boxes on the perf board was the cause of the noise. I could bypass the contactor by manually pushing it in but it wouldnt stick. Could there be an electronic failure? Like i said though, it's random when the unit decides to work and when it doesnt. I finally got it to start on "road" but it would turn off with the alarm and fault code ENG OIL. I have changed the oil and the filters, as well as filled the oil level and it still gives me that same fault code. could there be a sensor that may have gone bad? I hope someone reads this, as im in need of some help. I just dont understand it, is all. I have never worked on these units before. Thank you in advance
~Sean
The units are using shore power as their source and i find that the units are rated for 230v, 60 hz, 3 phase. The units are powered from a generator to a "spider box" then to the reefer units. The volts that i picked up from the unit is 205. I understand that having low voltage can cause a lot of malfunctions? There have been a bunch of the little black display screens that have gone bad and i believe that its an electronic issue, but has to deal with the electricity being fed to the reefer unit. I just dont understand why so many of the display screens have gone bad. Another thing that goes bad or that i get an error code is ALT AUX, which i know now is the alternator. Here's the catch. With the unit, it will work fine half the time on shore power(randomly cuts off when its been running for an hour or two and gives an alarm). I have switched to "road" and it wouldnt start up on road or on shore power for an entire evening, but when i tried to get it working in the morning the next day, it didnt work until the second time i tried to turn it on even later in the morning. I hear a lot of clicking and buzzing from inside the micro processor box and i noticed that one of the little black boxes on the perf board was the cause of the noise. I could bypass the contactor by manually pushing it in but it wouldnt stick. Could there be an electronic failure? Like i said though, it's random when the unit decides to work and when it doesnt. I finally got it to start on "road" but it would turn off with the alarm and fault code ENG OIL. I have changed the oil and the filters, as well as filled the oil level and it still gives me that same fault code. could there be a sensor that may have gone bad? I hope someone reads this, as im in need of some help. I just dont understand it, is all. I have never worked on these units before. Thank you in advance
~Sean