Aaaaarrrggghh. BEC problems

[TheDarkPassenger]

Badly needing some advice.

Blade 550x, ESC went bang, so ordered the CC HV 120. After wrestling with soldering finally got it on today.

Used a receiver pack to power the AR7200BX to allow me to set up the endpoints.

All well, so next test is to take of the receiver power and power through the BEC (standard e-flite one).

The battery connects to the ESC power leads, which also have leads to power the BEC soldered on.

Connected the battery, then connected the BEC leads to the BEC, a bang from the BEC and no power from the BEC.

Any thoughts/questions appreciated to help me work out what I've done wrong.

I also assume I'll need another BEC, any recommendations?

[GIXERMAN]

Either a decent bec gryphon or similar or a life pack direct into beastx

[parksy]

Hi DP, I take it esc bec was disabled, ie red wire removed from plug if necessary. Other than that, shouldn't esc to bec to receiver connections be made before plugging in battery? Something has shorted so it didn't like something you done.

[brin]

bit of a mistery .the 120 does not have a built in bec.so what has the bec been pluged into on the other end

Hi DP, I take it esc bec was disabled, ie red wire removed from plug if necessary. Other than that, shouldn't esc to bec to receiver connections be made before plugging in battery? Something has shorted so it didn't like something you done.

[TheDarkPassenger]

Hi DP, I take it esc bec was disabled, ie red wire removed from plug if necessary. Other than that, shouldn't esc to bec to receiver connections be made before plugging in battery? Something has shorted so it didn't like something you done.

I did indeed plug in the BEC after plugging the battery to the ESC.

For my understanding, why would the order of connection be important?

[RcRotaryMadness]

I'd go for a decent bec or better still a separate LiFe pack.

[brin]

When i looked at the 120 it had three wires on the plug for the rx and from my understanding the red one should be cut off and then your rx is powered through the BEC.
its a long time since i did any of this so cant be sure.

[mattscupoftea]

Hi Kev. Go for the Life pack - It stays as a separate part of the battery system so if (for example. . . ahem. . . not that it has happened to me twice or anything) something happens to your Lipo in flight (ie a lead coming unsoldered) you still have full servo control. From experience it's a good idea. I use a sanyo eneloop and it has never needed charging since i got it. I think it charges off the circuit when it needs it.

Can't wait to see you flying the 550!

[chadvandonkey]

+1 on the Life RX pack. Had the same choice to make with my Goblin 700 (BEC vs RX pack) and went for the life pack with no regulator. Align servos are 6v so the 6.6v of the life pack is fine and more importantly you can power up the radio without powering up the main motor and therefore blades.Just make sure you are running 6v or HV servos before putting a life in there. The AR7200BX is fine for 6.6v too.

[scallybert]

When i looked at the 120 it had three wires on the plug for the rx and from my understanding the red one should be cut off and then your rx is powered through the BEC.
its a long time since i did any of this so cant be sure.

Following on from your FB post, the CC ICE 2 120HV (as you say) has no BEC, and an opto-isolated throttle. Castle Creations | Phoenix Ice2 HV Controllers .

AIUI, the red lead on the throttle servo plug is required, to power the Rx side of the opto-isolator circuitry. [My G5s with old pre-ICE 45HVs were like this.]

This is a different scenario from where there output from an ESC's onboard BEC must not be connected to the output of an offboard BEC.

However, I still have no clue as to why the stuff went bang.

Ah, hang on a second...

DP says the BEC is powered from the LiPo, same as the ESC; but it's an HV ESC - which suggests the lipo is more than 6S. A lot of BECs (eg 'CC BEC') are only good to 6S.

Is your BEC capable of running at the voltage the LiPo is putting out ?

[brin]

as far as i know kevin is only using 6s

Following on from your FB post, the CC ICE 2 120HV (as you say) has no BEC, and an opto-isolated throttle. Castle Creations | Phoenix Ice2 HV Controllers .

AIUI, the red lead on the throttle servo plug is required, to power the Rx side of the opto-isolator circuitry. [My G5s with old pre-ICE 45HVs were like this.]

This is a different scenario from where there output from an ESC's onboard BEC must not be connected to the output of an offboard BEC.

However, I still have no clue as to why the stuff went bang.

Ah, hang on a second...

DP says the BEC is powered from the LiPo, same as the ESC; but it's an HV ESC - which suggests the lipo is more than 6S. A lot of BECs (eg 'CC BEC') are only good to 6S.

Is your BEC capable of running at the voltage the LiPo is putting out ?

[tomatwalden]

Any thoughts/questions appreciated to help me work out what I've done wrong.

I've been thinking about this and can't come up with anything different from how mine is rigged. The only difference I can see is that I normally have the BEC wires permanently connected so that when the LIPO is plugged in, power goes to the ESC and BEC simultaneously. Can't think of any reason why plugging in the BEC after the ESC would cause a problem, but then I'm no sparky!

Try sending a PM to Xygax (Steve) - he's pretty hot on this sort of thing ...

@scallybert - yes, the 550X is a 6S machine despite the 120HV being a popular ESC for it.

[parksy]

Hey DP, did you find out why original esc went bang? Have you checked your wiring all through? It hasn't rubbed somewhere and shorting on frame? Polarity ok throughout connection? I dunno the particulars of each component, but check instructions of each to make sure wires are correct. ps I only suggested connecting esc to bec to receiver before battery because yours went 'bang'. Good luck. Steve

[TheDarkPassenger]

There is nothing exposed that is touching anything it shouldn't so I'm still confused.

Got a replacement BEC; a Thunder Power BEC-8 unit was recommended.

The best I can think of is that connecting BEC after current is already running to the ESC is a bad thing to do.

Will try it tomorrow and hopefully not make a second BEC go bang

[parksy]

Fingers and toes crossed! Good luck TDP
Make sure wires from bec to receiver are round right way in the plug! Same goes for esc plug to receiver. Double check every connection, then pray it don't go pop. If it does, I'm out haha.