Single wire PowerLite Alternator for Xflow

[DW]

Hi

I've bought a Powerlite alternator for my Xflow and the blurb says:

conversion to single wire aids fitment and classic and competition cars do not require multiple connections.

I've fitted it using the existing 3 x wires onto the spade connectors. I've a battery cutoff switch, so all three wires get melded into one on the way to the cut off switch.

 

If I replace these wires with a single wire, does it go onto the bolt with nut connection on the alternator rather than the spades?

 

 

David

1700XF: click here

[jonboylaw]

Hi David,

I have no idea, but try calling them to ask the question:

 

PowerLite is a registered trademark of:

 

Eurolec Components (Midlands) Limited

Moor Street

Brierley Hill

West Midlands

DY5 3SU

 

Tel: 01384 261984

Fax: 01384 74552

 

Jon

[Mick Day]

Do a Google on single wire alternators: I came up with here.

 

"First off, realize that the alternator needs field power in order to

generate. Unlike an older generator, the alternator's tiny bit of

residual field is not enough to get things rolling. In a

conventional setup, power is applied to the voltage regulator from

the ignition switch. The voltage applied to the voltage regulator

and field is also the reference voltage that the regulator controls

to. The regulator excites the field at whatever level it takes to

keep the voltage at the input terminal at 13.8-14 volts. That means

the output terminal voltage of the alternator may be (much) higher,

depending on the voltage drop in the wiring between the alternator

and battery. If the vehicle has an ammeter, then there will be

voltage drop across that in addition to the drop through the

wiring.

 

The one-wire alternator must - by definition - regulate its output

voltage. The designer of the regulator has to allow for some

defined amount of voltage drop through the wiring to keep the

battery at the desired 13.8-14 volts. If the resistance in the

alternator circuit is higher than what was anticipated, then the

battery will be undercharged. If the resistance is lower, e.g., a

short, fat wire directly from the alternator to the battery, then

the battery may be overcharged. My experience with a number of 1

wire alternators is that the terminal voltage is set to 14.2-14.5

volts.

 

Two issues for manufacturers here. One, while an individual's

mildly over or undercharged battery may not matter much in the big

picture, for an OEM, having this happen to thousands of cars would

be a warranty disaster. Second, to keep the charging voltage at the

battery correct, a different regulator with different wiring

compensation would be required for each model. A logistical and

cost nightmare.

 

The other major consideration is field current control. A

conventional alternator draws full field current when the engine is

stopped. The reason it doesn't drain the battery is that the field

supply is switched off with the ignition switch. Since the switched

field power isn't available to the 1-wire alternator, engine stop

and start to turn the field off and on must be inferred from other

parameters. The 1-wire regulator detects engine stop by the

cessation of AC from the stator. This is reliable. Engine start

gets a bit more complicated. Since the alternator is not generating

until the field is applied, engine start must be detected by other

means. With the regulator I commonly use, this is done by looking

for the dip in voltage associated with engaging the starter motor.

If it sees a dip in voltage, it applies field and looks for stator

output. If no stator output, the field is cut off again.

 

The problem is, to be sensitive enough to detect engine starts under

all conditions (such as when the car is rolled off without engaging

the starter), the voltage dip detector has to be pretty sensitive.

In experiments I have done, I've discovered that the small dip

caused by switching on a single 50 watt driving light will trip the

field on. That means that the field will be momentarily turned on

from a wide variety of conditions other than engine cranking. It

won't be on long but it does consume some battery power.

 

Again, for the individual user, this isn't much of an issue. Most

1-wire alternators end up on hotrods and old cars with few

accessories and usually none that draw impulse current with the

ignition off. At most, if the dip detector ended up too sensitive

or the car has some load that trips it regularly, the only

consequence would be an occasional dead battery. Having this happen

over millions of cars would, for the OEM, again be a warranty

nightmare.

 

The 2 wire setup neatly addresses all these issues and so the OEMs

stick with that design."

[DW]

Called Eurolec.

 

What they mean by 'a single wire' is that you only need a wire for the ignition light. You do still need the 2 battery wires. Other than that, you don't need any other wires.

 

I had a 4th wire in the loom which I had connected but apparently don't need. So I've disconnected that and it still all seems to work. Think this must have been wired back to the ignition.

[jonboylaw]

Hi David,

 

Would it be possible for you to post up a wiring diagram?

 

Cheers,

Jon

[DW]

Hi Jon

 

This what I've got.

 

Link to Wiring Diagram for Powerlite Alternator