Battery Tie Open
-
I usually fire up Starship with external power in order to save the battery. Today I opted for a battery start and full checklist. Almost made it to 'Start Right Engine' when something tripped and all the power went out. I hooked up the external power, and when the EICAS came up, the message 'Battery Tie Open' appeared. I followed the abnormal procedure for the message, but the message stayed until I exited the flight, and it did not reappear the next time I loaded in. There doesn't appear to be a switch in the cockpit for this, so I'm wondering if this is something an A&P mechanic would need to fix IRL.
-
Just speaking as an A&P and Flight Engineer, with no experience working on Starship I may add! - I would say you would have a look as the possible causes and spend a little time fault-finding, but with electrical faults like that, particularly ones that go away after the TURN IT OFF-TURN IT ON fix there is usually no worries so long as it isn't a common occurrence.
Did you check for any popped CB's before you exited the flight? General rule for ANY failure in an aircraft, Breaker-Bus-Component!. Is the breaker popped, is the bus powered that it is connected to...then you look at the component. Just last week working on our last old RNZAF C-130 here in NZ and Coulsons had an issue with the Aux Vent Valve not closing during APU ground run and were discussing getting a replacement valve off another Herc 4 hours away etc. I went and had a look and yep Aux Vent Valve CB was out - popped it back in and you could hear the valve closing in the FD.
The RL Starship Maintenance Manual does state with Battery power on "If an electrical fault prevents closing of the battery bus-tie relay, the EICAS yellow BATTERY TIE OPEN caution message will display. The generator bus-tie switch must be placed in the MAN CLOSED position to power the LH and RH generator buses with battery power only." (24-31-00, Fig 2). So it could have just been a transient overvoltage or momentarily drawing too many amps etc.
Obviously in MSFS it is hard to know to what depth the systems are exactly modelled to RL, but I believe the Starship is pretty deep and have had starter CBs pop, but to answer your question it wouldn't be a major if all was good after a restart. The previous Herc I mentioned was actually on it's way to Canada and had some AP and other avionic boxes issues on the way into Kona, but did a total power restart on the ground and were good to go.
Hope that helps a bit - any Q's let me know
REF:https://www.bobscherer.com/Files/Starship/Maintenance%20CD/mm/122-590013-21B_Vol1.pdf
-
Sorry I never answered this, btw. I was away on a trip at the time. I did look into the code when I got home. There are actually numerous conditions that can prevent the battery tie from closing within my code, including its own failure (visible on the failures page of the tablet interface).
I would have responded, but I was struggling with how to answer, given that the many combinations of conditions are difficult to convey succinctly. The end result is a little easier to explain, which is simply that the battery bus does not connect to the center bus. You can witness this on the live electrical schematic page of the tablet interface too. I'm always here to try to answer your questions, though!
-
@OrionNZ @Black-Square thanks for your responses. I did check circuit breakers and none of them were popped. Interesting that the generator bus ties get a switch in the cockpit but the battery tie does not.
At this point my question is whether cycling power is a legitimate real-world solution to this issue, or it's a "sim thing".
-
@OrionNZ @Black-Square thanks for your responses. I did check circuit breakers and none of them were popped. Interesting that the generator bus ties get a switch in the cockpit but the battery tie does not.
At this point my question is whether cycling power is a legitimate real-world solution to this issue, or it's a "sim thing".
I actully found out that a batteyr bus tie happens if main battery is low like starting both engines on 80% charge on main battery only triggers a bus tie open and the only way to resolve this was for me to reset the battery back to 100%, not sure if that was the case for you
-
@4339ulrik22 that sounds similar to what I experienced. Probably drained the battery while running the checklist. I wasn’t at a location with a GPU so couldn’t charge the battery and had to go out to the menu and come back. If charging the battery fixed it for you, maybe it’s self-healing.
-
@OrionNZ @Black-Square thanks for your responses. I did check circuit breakers and none of them were popped. Interesting that the generator bus ties get a switch in the cockpit but the battery tie does not.
At this point my question is whether cycling power is a legitimate real-world solution to this issue, or it's a "sim thing".
@MarkS Cycling power (either system or entire aircraft) is definitely a real-world solution to a number of avionics problems (pretty much most TBH lol).
Also, we were always taught NEVER to use CB's as a 'switch' to cycle power to systems - so don't pop the CB for a malfunctioning system them reset it to try and 'cycle' the power to it to solve issues. However it is fine to reset a CB once after a 2 min cooldown as it may have been one-off transient volt/amp issue. Pops again and is U/S.
Awesome that BS has programmed in so much depth into his systems - gives people a taste of what it is actually like trying to deal with these mystery issues when you just want to fly lol.
-
@MarkS Cycling power (either system or entire aircraft) is definitely a real-world solution to a number of avionics problems (pretty much most TBH lol).
Also, we were always taught NEVER to use CB's as a 'switch' to cycle power to systems - so don't pop the CB for a malfunctioning system them reset it to try and 'cycle' the power to it to solve issues. However it is fine to reset a CB once after a 2 min cooldown as it may have been one-off transient volt/amp issue. Pops again and is U/S.
Awesome that BS has programmed in so much depth into his systems - gives people a taste of what it is actually like trying to deal with these mystery issues when you just want to fly lol.
@OrionNZ said in Battery Tie Open:
Awesome that BS has programmed in so much depth into his systems - gives people a taste of what it is actually like trying to deal with these mystery issues when you just want to fly lol.
I've worked very hard to supply these moments of inconvenient realism
-
I hope all of my airplanes feel that way, but Starship is really something special. I'm glad you're enjoying it!
