Interesting wiper motor caution

[knotflying]

Baz, I think, but not sure, that the standard auto fuses are already fast acting.

 

[Osprey]

Fast Acting?
The ATO blade fuses used by Ranger Tugs have a 135 % of current rating opening specification of between 0.75 S up to 600 S i.e. up to 10 minutes.
Parking Current
I set up a clamp-on ammeter to measure the wiper motor parking current. Since the parking current only flows for 1 second or so, the meter hardly has time to respond. Consequently the reading may be incorrect. The result I did get was a little over 2 A for two motors parking simultaneously. This test was done with a 5A ATO blade fuse in the parking circuit. I have decided that a 5 A fuse is adequate for my tug.

 

[baz]

I'm wondering what the Factory's advice/thoughts are about this wiper parking fuse of 15 amps appearing to be too large ?

 

[knotflying]

I did e-mail Andrew directly and made him aware of the situation in case he has not seen this thread. Knowing Andrew I am sure he will follow up with this.
Anyone want to buy spare parts for a wiper motor :lol:

 

[Binare]

Fuses protect wiring, not equipment. If the wire size is rated for 15amps, than it was wired correctly. The size of a fuse will never have an effect on whether equipment is faulty or not.

 

[DBBRanger]

Update: ..... I replaced the park circuit fuse with a five amp and tested turning on all the wipers and turning them off. As of this correspondence there has not been an issue with the five amp fuse blowing.....

My wiper park circuit had a 30A fuse in it!! I too have replaced it with a 5A fuse and will see if that protects it adequately.

 

[baz]

I did e-mail Andrew directly and made him aware of the situation in case he has not seen this thread. Knowing Andrew I am sure he will follow up with this.
Anyone want to buy spare parts for a wiper motor :lol:

Ditto... same here. 🙂

Andrew prefers being forewarned about these type issues before the thread get's out of hand with complaints. 😉

 

[knotflying]

Fuses protect wiring, not equipment. If the wire size is rated for 15amps, than it was wired correctly. The size of a fuse will never have an effect on whether equipment is faulty or not.

Bi are,

Your point is well taken. However there are two things I observed. The lead wire insulation going to the motor in the unit were melted and the wire itself was starting to burn. The manufacturer's literature states that a 5 amp fuse is to be used for a single motor and a 7 to 10 amp fuse if two motors are on one circuit. The interesting way that Ranger has it wired is with a switch circuit for each motor which I am assuming and hoping is a 5 amp breaker and then the park circuit that has the much larger fuse. Electricity will take the path of least resistance so once you turn off the wiper switch the park circuit will be taking over and hence you are now on a circuit that is using the much larger fuse. The wiring diagram from the manufacturer has only one fuse protecting both the switch side and the park side. With that setup the same fuse is protecting two different circuits. Doing it the way ranger did it, having the larger fuse on the park circuit is not appropriate. The smaller amp fuse should have probably blown before the wires that went to the motor started melting. The motor may have not been saved, but the potential of a fire starting was not present.

 

[Binare]

Right, if the manufacturer says one 5a fuse per motor and the diagram shows both circuits on the same fuse, thats the way it should be wired, no two ways about it. Sounds like the factory has 4 motors on a 20a fuse, if thats correct, they need get there stuff together and stop doing things this way, its a huge fire risk and is blatantly ignorant to what is deemed to be proper wiring.

 

[baz]

I had a reply from Andrew about this issue and he's looking into this.... so stay tuned as I'm sure he will chip in after his review of the situation.

 

[Brian B]

I have a 2010 25SC. My wiper park fuse was 20 amps. In this thread we now have 3 boats reporting 3 different size fuses, 15,20 and 30 amps.

 

[Osprey]

For the park circuit I believe it has been Ranger factory policy to use a parking fuse of 5 A per wiper motor on the circuit. The R21 boats have 3 motors so a 15A fuse has been used. R25, and 27 have 4 wiper motors so a 20A has been installed. At least this is my guess as to the 15 and 20A reports. As to 30A ?
It seems obvious to me a smaller fuse is required. In the event that a mechanical failure prevents one motor from parking, 20A or more flowing through one motor is going to cause serious motor over heating. In addition one should note that the AWG used in the parking circuit is #16. This is fine in that the motors normally park quickly which does not allow time for conductor overheating . However if there is a stalled park, continuous currents up 20A are beyond the maximum recommended for the AWG 16 runs in our boats. Be aware that turning off the wiper power switch located at the helm does not turn off power to the park circuit. In the event of a failed park, power to the park feature only terminates when the park fuse opens or when the park fuse is pulled.

 

[Binare]

For the park circuit I believe it has been Ranger factory policy to use a parking fuse of 5 A per wiper motor on the circuit. The R21 boats have 3 motors so a 15A fuse has been used. R25, and 27 have 4 wiper motors so a 20A has been installed. At least this is my guess as to the 15 and 20A reports. As to 30A ?
It seems obvious to me a smaller fuse is required. In the event that a mechanical failure prevents one motor from parking, 20A or more flowing through one motor is going to cause serious motor over heating. In addition one should note that the AWG used in the parking circuit is #16. This is fine in that the motors normally park quickly which does not allow time for conductor overheating . However if there is a stalled park, continuous currents up 20A are beyond the maximum recommended for the AWG 16 runs in our boats. Be aware that turning off the wiper power switch located at the helm does not turn off power to the park circuit. In the event of a failed park, power to the park feature only terminates when the park fuse opens or when the park fuse is pulled.

That is not how electricity works. A motor that draws 5 amps when operating correctly will still draw 5 amps regardless of the size of fuse. Doesn't matter if the motor is on a 100amp or a 5amp fuse, it still only draws 5amps. The problem is that if the fuse is oversized for the wire (including what the manufacturer recommends for pigtails and internal wiring) and the motor does malfunction, the wire is no longer protected by the fuse and could be a major fire risk, or at the very least, damage impossible to reach wire runs. Imagine what would happen in a big bundle of wires if one burnt up in an inaccessible location.

It sounds like the manufacturer recommends that both circuits be on the same 5amp circuit.

If that is true, I can't figure out why for the life of me, anyone would purposely create a fire hazard and wire it incorrectly by putting all park circuits on an oversized fuse that will definitely lead to wiring overheating if a motor fails.

Either way the motor would still have failed and probably needed replacement, but if wired correctly should not create a fire hazard in case of failure.

I would give the factory the benefit of the doubt until you here from them, I really can't picture them hap hazardly doing stuff like this on these expensive little boats.

That being said, I highly doubt the park circuit is rated for anything above what the running circuit is rated for, as a potential customer in the next few months and a Master Electrician, I'm very curious about this issue myself.

Does anyone have a wiring diagram, manual or manufacturer part number for these motors?

 

[knotflying]

I did replace my motor and the manufacturer's literature shows a 5 amp fuse and if two motors are used then 7-10 amps. Both park and switch are on the same circuit. I replaced mine with a 5 amp and so far so good. I would rather have a smaller fuse than a larger one.

 

[Binare]

I did replace my motor and the manufacturer's literature shows a 5 amp fuse and if two motors are used then 7-10 amps. Both park and switch are on the same circuit. I replaced mine with a 5 amp and so far so good. I would rather have a smaller fuse than a larger one.

Was it the same as the factory motor? Just curious.

 

[knotflying]

Yes, same exact motor.