Display for Totem CS-240 wiring question

[cwc]

I am working on the subject bike for a neighbor lady. The wires from the battery to the controller are a dead short inside the controller box. It looks like an electrolytic cap exploded.
I'm trying to determine if other parts of the circuit were damaged.
The hall sensors on the pedals as well as the ones in the motor seem to be operating as they should.
I applied voltage to the display but it wouldn't turn on.
The wires to the display are as shown below.
Red +36v
Blk -36v
White Brake signal
Green Comm Tx
Yellow Comm Rx
Blue Lock

What is the function of the the "Lock"
Do the "Lock" or "Brake signal" need some input to allow the display to turn on.

 

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Unless the display has sockets for brake sensors to plug into (which if the case, needs no connection for operation), its probably just carrying the signal for the display to show the brake sensor state?

Generally connecting the red battery voltage wire to the blue lock wire is a common pedelec controller bodge to run a bike without a display with only throttle speed control.

A common model that most pedelec controllers employ is to collect and save the configuration parameters (wheel size etc..) within the display rom, only communicating and passing these to the controller mcu on system startup.

However there are many brands of controller and displays.. So details of the specific controller and display used may encourage more than a general response?

EDIT depending on the bike a new controller/display combo is not that expensive and can be a significant upgrade over the basic controllers some bikes ship with.

 

[cwc]

Thanks for the reply.
So connecting the red battery voltage wire to the blue lock wire connects the lock to the 36V line? Or do you need to reduce the 36VDC to a digital level?

I have attached photos of the controller and display. The bike is 6 years old and Totem is unable to provide any more info than I have included so far.
If I read the manual correctly the paddle on the display steps through the 5 levels of pedal assist.
The markings on the back of the display are:
2001805 0183
CDC1.V14.36V.1V5

 

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A simple short/connection between the red and blue controller display connections will turn on a working controller for throttle use in most cases. Under pas control the controller needs i/o (the display) to change the pas level as the default is 0.

I dont get much from the display markings but the controller is a pretty generic device with limited i/o, just display and pas sensor connections beyond battery and motor? no brake sensors or throttle inputs?

If the lcd is receiving battery voltage and a good ground connection and fails to start up and display anything, it too probably has a fault from the 'incident', It should start up and if failing to handshake with the controller display some error.

If skilled in electronics there are a few fault finding walkthroughs Grin ebikes have a good knowledge base..

Many would just get a replacement controller/display KT brand are popular with a wide range of compatible lcd displays and a full range of configurable settings but also the chenglish manual, cheaper options are available with less display options and less options for configuration. The Peak amp capacity is used when describing controllers, a 15a controller would be the 'standard' replacement for your 14a controller.

 

[cwc]

Sorry about the delay in responding. I've got several irons in the fire and a couple of them took me away from this.

Ref. your questions:
There is a switch in the brake cable assembly that signals the display and controller if the brakes are applied.
There is no variable throttle, just the lever on the side of the display that will turn on the motor even with no pedaling ONLY if the bike is already moving.
The power is selected in 5 steps controlled by the display pushbuttons.

I've found that Totem can supply a controller, but a display will not be available until next year sometime (which sounds a lot like never to me).

So now I'm looking at buying a controller and display as suggested above and would like to get one that works the same way as the original.

Questions:

The motor is rated at 250W. The controller is rated at 14A which at 36VDC make a little over 500W. Is that (apparent) mismatch normal?

If KT is a good brand, is there a preferred vendor? The ones like Amazon and Walmart are a little short on specs and I'm guessing are not the best prices.

Below is the information I've been able to deduce for the existing controller.

 

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Buy a KT (Ketung) brand controller and display from any vendor, just be mindful that an ad that omits to specify a sine wave controller is probably going to ship a cheaper square wave controller. The Chinese seller topbikekit is recommended on a local forum not so much for the site layout and search (not the best) but for range and options..
Might also be worth checking the chenglish of the manuals for config info in advance too.. LCD-03 manual for example.
(worst bits are imho the pas sensor config table and description, i resorted to trial and error (iirc 3 options so.. no biggy)

For the motor-on paddle a trigger switch speed controller can be fitted and configured..

You can buy cheaper controllers but will be limited in display options and config ability.


Didnt take you long to spot the problem with all the regs limiting motors by rated wattage eh Yes thats the score.. And you forgot to consider when fully charged your 36v battery has a 42v charge But that is the Peak output capacity of the controller only expected to be expended under extreme load -pulling away loaded up with lots of shopping or climbing hills..
Also losses of efficiency and heat generation friction with the rd etc have some impact too

One possible reason for shipping with a 14a and not 15a controller is battery limitations?? ( unlikely but WORTH CHECKING) If your controller attempts to pull more amps than your battery can provide - well if the BMS fails to cut out that could be VERY BAD.. But if your battery can handle it a 15a or 17a controller should be fine with a 250w rated motor under most ridding conditions..

No mention of brake sensor input in your diagram or did i miss it? If not fitted i would urge you to consider adding them, if only as an emergency contingency..

 

[cwc]

I looked at topbikekits and was able to get pretty much everything I needed but decided to check the existing display again and found that when I turned on the battery switch it actually worked. DUH!!! Don't know where my brain was when I tested it the first time
Anyway I saved all the info in case something else fails.
I'm just going to order the stock controller from the vendor because I have several other projects going.
Thank you for taking the time to help me with this.

 

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It happens.. glad your sorted.