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[steve62]

Hi, my second post and I'm probably about ask a stupid question,
I want to know if I can wire 2 viper marine 20 esc`s to a common on/off switch, I think I know but would like some advice if poss.
cheers in advance

[unbuiltnautilus]

I wouldn't be comfortable wiring both switches into one set of contacts, however if you use a Double Pole On/On switch and wire one speed control  switch wire pair to one set of contacts ( lets say left side middle and one end ) and the other speed control switch wire pair to the other side, that should be fine. As this type of switch is essentially two three pin on/off switches glued together side to side! Hope that makes sense?

[Martin (Admin)]

Usually, a power switch is on the battery side, like a wall socket, isolating all the electrics in the boat.



 
http://www.modelboats.co.uk/news/article/but-i-don-t-understand-electronics/18054

[dougal99]

Why not locate both switches together and activate them at the same time. Possible with one finger. Save a lot of rewiring.

Word to the wise, don't forget to disconnect the red wire of one of the ESCs so that the RX is only receiving power from one source (BEC).

[malcolmfrary]

You can't safely combine the two switches that come with the ESC.  They don't connect directly to the power, but control a circuit inside the ESC, which is why they can be as small as they are.
The easiest option is to place these two switches alongside each other as in Dugal99's post.  And, from looking at a project where this was done, put them where they are easily visible.  Black switches in a dark spot can be annoying.
If an actual power switch is to be used it needs to be rated to carry the full current.  This normally means a bulky switch that needs a strong mount to stand up to operating the switch.

[Skimmer Fan]

PM sent

[Skimmer Fan]

malcolmfraryWould the wiring diagrams work and could the esc switches be left in the on position?
With 2 20amp ESC's what rating would the wire and switch have to be?

[malcolmfrary]

malcolmfraryWould the wiring diagrams work and could the esc switches be left in the on position?
With 2 20amp ESC's what rating would the wire and switch have to be?

The drawings would sort of work.  An overall fuse is there to protect the battery against whatever the boat offers in the way of a fault, and the rest of the boat against the heat that a fault could create in the wiring.  That includes the major fault liability, the wiring to the switch.  It should therefore be between battery positive and switch.  ESCs and their wiring are generally well sealed against damage, wiring to a switch less so.
With an overall power switch, the ESC switches would be left on.
The earlier suggestion that the fuse vale should be more than the motors draw under use, but less than the total ESC rating is still valid.  The important figure that gives the current through the fuse is not the ESC rating, but the work that is expeced from the motors.
To add a bit of complexity, it helps to remember that switches have several parameters.  Two Three of interest are switching current (what it can switch on or off) and constant carrying current, (what it can carry after the contacts have settled and stoped bouncing).  The constant current figure tends to be considerably higher than the switching maximum. Voltage is good to know, but should not be a problem at model battery voltages.
Wire standard?  I tend to look at what has been used for car accessories for similar currents and go for that.
A 20 amp ESC does not, a such, draw 20A, that figure is the current draw beyond which it will let the smoke out.  Good practice is to determine by testing what current is drawn, double that for safety, buy the next value up from that.  You can do such testing with brushed motors before buying the ESC.  With brushless motors, a correctly set up and specified ESC is an essential part of the motor, without which is is simply a device for converting battery charge into heat.
My personal preference is to just unplug the battery before taking it out for charging.

[dougal99]

How would the battery leads be attached to the esc if the original switches are left in situ?

[malcolmfrary]

How would the battery leads be attached to the esc if the original switches are left in situ?

Component Shop, among many other suppliers, do a selection of Y leads, depending on the arrangement, for connecting either two ESCs to one battery, or two batteries to one ESC.  Distribution boards are also available.

[barriew]

How would the battery leads be attached to the esc if the original switches are left in situ?

The switches on Viper, and other Mtroniks, ESCs are not in the power supply. That's why they can't be used to totally isolate the ESC. They only switch the electronics, not the power to the motor.


Barrie

[BeeJay UK]

Usually, a power switch is on the battery side, like a wall socket, isolating all the electrics in the boat.


http://www.modelboats.co.uk/news/article/but-i-don-t-understand-electronics/18054



I'm pretty OK with electronics, I used to be a school science technician in a previous life, however that link is to a really good, useful article.

[DaveM]

I'm pretty OK with electronics, I used to be a school science technician in a previous life, however that link is to a really good, useful article.

Well - many thanks for that, Beejay. I can't remember the last time I had a big tick from a science teacher. 
Dave M

[dougal99]

How would the battery leads be attached to the esc if the original switches are left in situ?

I must not post so early in the morning before my first coffee.  Yet another senior moment 

[radiojoe]

To answer the original question about wiring two ESCs to one switch well I did just that on one of my warships, I always liked to have the on/off switch on deck somewhere disguised as a vent or ammo box on one of my ships I used two 15amp mtronic ESCs to run two motors and I wired the two ESCs to one switch operated by sliding an ammo box, some say it's not advisable but mine worked fine with no problems at all, of course I only used one of the BECs.




Joe.

[malcolmfrary]

To answer the original question about wiring two ESCs to one switch well I did just that on one of my warships, I always liked to have the on/off switch on deck somewhere disguised as a vent or ammo box on one of my ships I used two 15amp mtronic ESCs to run two motors and I wired the two ESCs to one switch operated by sliding an ammo box, some say it's not advisable but mine worked fine with no problems at all, of course I only used one of the BECs.




Joe.

A bit of good luck involved there.  If the two black wires had not been connected identically, at best one of the ESCs would have been permanently on or off. 
If the switches are wired to just present the main battery voltage to the internal electronics, that is why it can work.  But there is no way of knowing if the same arrangement happens on other ESCs (including later marks of the same model).  And with different designs, anything is possible. 
If hiding a switch under a sliding box, best to make the box big enough for two switches, have them both slide together.