Balmar 150A Alternator with MC-614 Regulator Issue

[DayDreamer41]

Hope I can get some insight into the issue I am experiencing.

A couple of seasons ago I upgraded our charging system to include a Balmar 6 series 150 Amp alternator coupled to an MC-614 external regulator, I also installed a SG-200 battery monitor system.
Everything was working perfectly until this spring when I commissioned the boat a couple of weeks ago.
When plugged into shore power the SG-200 shows the correct voltages and amperage charging curves from the onboard invertor/charger, but when on engine power the SCG-200 indicates the correct charging voltage (according to the MC-614 setup see attached) but negative amps, the higher I rev the engine the more negative the amps?
I have removed the alternator and checked the diodes and all is right there, which correlates to the voltages I am seeing on the MC-614.
I am guessing that I might have a bad temp sensor either on the alternator or the battery? which would cause the alternator to reduce output, but I am not certain on how to go about checking this, I would like to hear from the experts on this issue.
I did purchase the system from Rod at Compass Marine, I am hoping that I can get some information to help remedy this issue.
Thanks in advance
Mark

 

[Davidasailor26]

If you’re getting a good charge voltage the battery must be charging. Is it possible that the ground from the engine got disconnected and then reattached to the battery side of the SG-200’s shunt, instead of the load side?

 

[Maine Sail]

Shunt is most likely wired incorrectly….

 

[DayDreamer41]

If you’re getting a good charge voltage the battery must be charging. Is it possible that the ground from the engine got disconnected and then reattached to the battery side of the SG-200’s shunt, instead of the load side?

I did not disconnect the batteries nor the shunt all I ever do in the fall when laying the boat up for the off season is ensure the batteries are full of water and fully charged, open the isolation switches and turn off the DC breaker. The shunt which monitors the house bank shows the correct voltage and positive amps which on shore power but when being charged from the alternator the SG-200 shows charging voltage but negative amps, the higher the engine is rev'd the more negative the amps are indicated.

 

[jviss]

shows the correct voltage and positive amps which on shore power but when being charged from the alternator the SG-200 shows charging voltage but negative amps, the higher the engine is rev'd the more negative the amps are indicated.

That is weird. Now, think about this, did it always show negative amps when being charged, or is this the opposite of what it used to do? Unless someone changed the wiring I can't imagine how things would reverse that way, unless there's some crazy programing parameter in the SG200 that got changed or lost somehow.

Are you sure it's charging when on shore power? Positive amps could be that the house bank is discharging, no?

Can you report the values you saw? How many positive amps when on shore power? What loads were on? Etc....

 

[DayDreamer41]

Shunt is most likely wired incorrectly….

Rod, the SG-200 has not been altered since the installation spring of 2020 and is indicating properly when the batteries are being charged by the invertor/charger.

Do the temperature sensors for the alternator or battery fail open?

Or do they fail high? failing high would make sense to protect the equipment they are monitoring.

If either were to fail, how would it effect the regulators output to the field windings? I would imagine that the field winging voltage would drop to 0, but this should not cause a negative amp draw from the house bank?

Could the alternator ever become a load on the batteries? causing a negative amp draw?

Sorry for the ramblings thinking out-loud, it is just interesting that the SG-200 indicates correctly when the batteries and being charged by the invertor/charger and indicating correct voltage and negative amps when being charged by the engine. There is 0.0 amps indicated when shut down nothing is turned on, but when being charged by the alternator the negative amps go even more negative when a load is introduced.

Mark

 

[jviss]

Why are you zeroing in on the temp sensors. You can just disconnect those and things should still work in the nominal case.

One really useful piece of test equipment is a DC clamp Ammeter. These are usually also a DMM, so a very useful piece of equipment.

 

[DayDreamer41]

That is weird. Now, think about this, did it always show negative amps when being charged, or is this the opposite of what it used to do? Unless someone changed the wiring I can't imagine how things would reverse that way, unless there's some crazy programing parameter in the SG200 that got changed or lost somehow.

Are you sure it's charging when on shore power? Positive amps could be that the house bank is discharging, no?

Can you report the values you saw? How many positive amps when on shore power? What loads were on? Etc....

At this point all the house breakers are open, when I do introduce a load and the engine running the amps indicate more negative, but when on shore power the amps start negative but index to positive as the invertor/charger increases its output offsetting the load.

I asked myself if the system ever indicated positive amps with the engine running and to be honest I don't remember (CRS), how can I have charging voltage (indicated both on the SG-200 and the panel voltmeter) and have a deficit amperage, is that even possible? and again this is with all circuit breakers off, the minute I introduce a load the SG-200 indicates more negative.

Mark

 

[DayDreamer41]

Why are you zeroing in on the temp sensors. You can just disconnect those and things should still work in the nominal case.

One really useful piece of test equipment is a DC clamp Ammeter. These are usually also a DMM, so a very useful piece of equipment.

I have a clamp on, just didn't have it with me when at the boat the other day, I do have a Fluke 87A as a multimeter which is also indicating charge voltage. As for the temp sensors, when coupled to the multistage regulator the field winding voltage will be reduced as the temperature increases, if the temp sensor fails high it would in theory shut down the field winding voltage, but that would still not explain the negative amps. To be truthful I am baffled and reaching for any plausible explanation.

 

[jviss]

if the temp sensor fails high

This doesn't make a lot of sense to me, I would think a temp sensor, i.e., a thermocouple, would fail either open or short.

Anyway, it's important to figure out what's really going on rather than what the SG200 may be reporting. For example, I can't imagine how increasing the RPM will cause the alternator to suck current out of the batteries.

Get things running and use your current clamp and DMM to measure and record what's really happening. Is the alternator putting out? What's the alternator current? What's the battery voltage? What's the current flowing to the load panel? And so on.

 

[jviss]

Let me put it this way. If the engine is running, no house loads are on, the battery voltage is "up," like above the resting voltage, maybe even up to the acceptance voltage setting (14.4V, or 14.8V, or something), then, I can assure you, current is flowing into the battery - regardless of what the SG200 says.

Please know, there's no way that I know of that an alternator can suck power out of a battery, such that when you increase the RPM it sucks even more. Think about it. Where would the energy go? It could only go to heat, and the alternator would soon burst into flames! But, it just doesn't work that way. An alternator works by impressing a voltage upon the load (battery) and supplying the current necessary to maintain that voltage, in concert with the voltage regulator.

Are you sure no one else did anything to your boat, like maybe the boat yard?

 

[dlochner]

Do you have a service disconnect on the alternator?

Did you check the alternator output fuse?

Either of these could block the alternator's out put, which would cause the battery to discharge because no charge current is flowing to the batteries.

I've never had a problem with the fuse.

 

[Maine Sail]

How about a photo of the shunt wiring? Where is alt B- wired?

 

[DayDreamer41]

Do you have a service disconnect on the alternator?

Did you check the alternator output fuse?

Either of these could block the alternator's out put, which would cause the battery to discharge because no charge current is flowing to the batteries.

I've never had a problem with the fuse.

Yes on the service disconnect and yes it is closed

Alternator output fuse? the fuse for the regulator or the main DC fuse? - I haven't check the fuse but with voltage present above the battery norm I presumed the fuse was intact.

 

[dlochner]

Alternator output fuse? the fuse for the regulator or the main DC fuse? - I haven't check the fuse but with voltage present above the battery norm I presumed the fuse was intact.

The fuse between the alternator and the battery or positive busbar.

 

[DayDreamer41]

How about a photo of the shunt wiring? Where is alt B- wired?

I won't be to the boat until tomorrow or Wednesday I will take a photo then, if I understand your question correctly the second plug, "Smart Link" is not wired, the plug is vacant and the starter battery is not in the circuit. AUX-1 Positive (Orange) & AUX-2 (Orange/blk) are not wired. The, "To Load -" is wired to the negative bus bar and the, "Battery Negative" is wired to the house bank.

 

[jviss]

A great philosopher once said "when something seems contradictory, question your premises." There are just too many odd things about what you report, and you tend to use language that's not common in this field, or that completely makes sense. Like "charging curves," "indexing to positive," and so on.

when on engine power the SCG-200 indicates the correct charging voltage (according to the MC-614 setup see attached) but negative amps, the higher I rev the engine the more negative the amps?

This means your shunt is wired backwards.

I have removed the alternator and checked the diodes and all is right there, which correlates to the voltages I am seeing on the MC-614.

Can you be more specific? How does a check of the diodes correlate to the voltages you are seeing? Doesn't make any sense to me.

when on shore power the amps start negative but index to positive as the invertor/charger increases its output offsetting the load.

 

[DayDreamer41]

A great philosopher once said "when something seems contradictory, question your premises." There are just too many odd things about what you report, and you tend to use language that's not common in this field, or that completely makes sense. Like "charging curves," "indexing to positive," and so on.

This means your shunt is wired backwards.

Can you be more specific? How does a check of the diodes correlate to the voltages you are seeing? Doesn't make any sense to me.

When I removed the alternator I checked the function of the diodes to ensure they were intact, thinking that I had a bad diode, I then replaced the alternator and reviewed the output voltage as it relates to the programing on the MC-614, this appeared to be normal, starting 14.9 for bulk, stepping down to 14.7 for absorption, the finally to float voltage of 13.5.

When charging on shore power when a load was introduced the SG-200 will show negative amperage for a short period of time which I presume ramps up the invertor/charger to come off float voltage up to 13.7 V.

Sorry for the confusion and I truly appreciate the input.

What I don't understand is, if the shunt is installed with the load and battery terminals reversed why would it show positive amperage while charging on shore power and not show charging correctly while on the alternator.

I will certainly check all these suggestions when at the boat tomorrow or Wednesday.

Mark

 

[jviss]

starting 14.9 for bulk, stepping down to 14.7 for absorption, the finally to float voltage of 13.5.

This doesn't make sense to me, as I understand the bulk phase is a constant current phase; I'l have to read the regulator manual and see. I understand the 614 and 618 are very similar, is that so?

What I don't understand is, if the shunt is installed with the load and battery terminals reversed why would it show positive amperage while charging on shore power and not show charging correctly while on the alternator.

Yea, I don't get it either. I'm thinking about it. Boy, if you had a schematic that would be great!

 

[Hayden Watson]

This doesn't make sense to me, as I understand the bulk phase is a constant current phase; I'l have to read the regulator manual and see. I understand the 614 and 618 are very similar, is that so?

Yea, I don't get it either. I'm thinking about it. Boy, if you had a schematic that would be great!

Your understanding of bulk being CC is correct. I think maybe the understanding of bulk set voltage is the part that is confusing.
It is better expressed as "the voltage which will trigger the reduction to absorption voltage ".

Let's say we're at 12v with 100a charge. The voltage will gradually increase at constant current 100a until the second that the voltage hits 14.9. The current immediately drops significantly until the voltage drops to 14.7. The voltage then stays at 14.7 as the current slowly decreases until the absorption time limit is reached. Then the voltage is held at 13.6