Automatic Power Selector... why?

[dhays]

So I have been doing more hunting around the boat recently trying to identify parts of the electrical system that I've been ignoring for the past 8 years. Here is an example that has me stumped.

This Automatic Power selector is installed on the boat and feeds the house circuit that, controls the power to the solenoids that connect the various high loads to their respective batteries. This device is really unknown to me but appears to be used primarily with ZF Microcommand controls. I can understand its application for that, as it helps to ensure that if you lose power in one battery bank, it will quickly switch to the secondary bank so that you still have control over your engine.
ZF Automatic Power Selector

The thing is, I don't have electronic controls on my engine. They are cable. The throttle is a cable control. So the only reason I can see for having this is to be able to power the solenoids that keep the engine connected to its battery, the thrusters to their bank, and the House bank to the house battery. It is setup with Source #1 as the House, and Source #2 is the start battery. I don't have a problem with this being there other than it takes up extra space on the DC bulkhead AND it looses about .6v. The output from the Load is about .6v less than the input.

So my question... is this normal behavior for these things? If so, that seem odd. If not, is it a sign that this thing is failing? I would be tempted to just get rid of it. However, I'm going to swap the house agms for lithium and I suppose there is the very small chance that their BMS could shut them down, then it would be nice to have that circuit fed by another bank.

 

[Delta Riverat]

I would get rid of it for 2 reasons;

1) It drops half a volt which is way too high for a switch.
2) The max load is 70 amps. Seventy amps? You must be joking. Probably another reason it drops half a volt.

 

[Portage_Bay]

So I have been doing more hunting around the boat recently trying to identify parts of the electrical system that I've been ignoring for the past 8 years. Here is an example that has me stumped.

This Automatic Power selector is installed on the boat and feeds the house circuit that, controls the power to the solenoids that connect the various high loads to their respective batteries. This device is really unknown to me but appears to be used primarily with ZF Microcommand controls. I can understand its application for that, as it helps to ensure that if you lose power in one battery bank, it will quickly switch to the secondary bank so that you still have control over your engine.
ZF Automatic Power Selector
View attachment 158691
The thing is, I don't have electronic controls on my engine. They are cable. The throttle is a cable control. So the only reason I can see for having this is to be able to power the solenoids that keep the engine connected to its battery, the thrusters to their bank, and the House bank to the house battery. It is setup with Source #1 as the House, and Source #2 is the start battery. I don't have a problem with this being there other than it takes up extra space on the DC bulkhead AND it looses about .6v. The output from the Load is about .6v less than the input.

So my question... is this normal behavior for these things? If so, that seem odd. If not, is it a sign that this thing is failing? I would be tempted to just get rid of it. However, I'm going to swap the house agms for lithium and I suppose there is the very small chance that their BMS could shut them down, then it would be nice to have that circuit fed by another bank.

Find out what it powers. Disconnect the load side and see what doesn't work.

What do your engines require to run? An electric fuel solenoid in an energize to run system? Any electronic engine controls, not throttle and shift.

 

[Delta Riverat]

If it drops half a volt at 70 amps it is dissipating 35 watts. Thirty five watts on some little contacts will get really hot.

 

[luna]

The Automatic Power Selector likely does not feed the house circuit, nor are the thrusters likely connected to it as a load.

It does what its name implies, selects the higher of any two connected power sources (they don't have to be batteries) to power whatever you connect to it as a load. The load is often just the ZF Microcommander controls, nothing else, unless you also deem it critical (your VHF?) by connecting it as a load.

The controls for shift and throttle are what most people would consider critical. As a result, it would be nice if they had a back up power supply. This device does that by selecting the highest voltage of either of the two power supplies (batteries) that are connected to it, thats it. Nothing more. The batteries themselves are never connected together.
This way the engine controls hopefully have a separate, secondary, workable voltage source.

Even though your engine's throttle and your gear's shift selection is done by cable at the engine/gears, the fact that you have this device tells me that these cables only go to a box about 10" square and 8" thick, likely in the ER, which is only wired to your controls at the helm(s). Inside the box are the motors, cable connection hardware and controls that actually pull/push the cable. You are almost "fly by wire" as your actions at the helm only produce an electrical signal. No control cable is pushed by the helm levers.

This device is a diode based selector and as a result the voltage drop through the device is said to be 0.35 to 0.45 Volts depending on load. If you are measuring 0.6 volts, make sure no voltage drop from the conductors is included.

The device, although branded ZF is likely made by Newmar out of Newport Beach CA. which uses as a motto "A Mission Critical Electronics Brand." How fitting!

Here is a link to their info. on the product. Doesn't it look similar? Stickers are easy to make.
Newmar generally mades good stuff, albeit you won't find it on your phone.

Automatic Power Selector | 12V DC | 24V DC | 48V DC | 70 Amps to 160 Amps | Mobile Mount | Newmar Powering the Network

Automatic Power Selector by Newmar Powering the Network: 12V DC, 24V DC and 48V DC, 70 Amps to 160 Amps. The Automatic Power Selector (APS) is a solid state device which enables installation of a seamless, redundant power system for critical electronic loads. It selects the higher voltage of two...

www.poweringthenetwork.com

If it was me, I would confirm what powers it (both feeds) and what are the loads. Once I'm happy with that, I would keep it as it provides a useful service.

 

[DDW]

It may also be powering the engine electronics. I assume you have a common rail engine, it will stop instantly without 12V power.

 

[Delta Riverat]

Ignore everything I wrote, the cables threw me.

Indeed there is a ZF Mathers control box that takes cable inputs and uses servo motors to do cable outputs. Only 3 grand each.

 

[psneeld]

....poor post

 

[twistedtree]

The Automatic Power Selector likely does not feed the house circuit, nor are the thrusters likely connected to it as a load.

It does what its name implies, selects the higher of any two connected power sources (they don't have to be batteries) to power whatever you connect to it as a load. The load is often just the ZF Microcommander controls, nothing else, unless you also deem it critical (your VHF?) by connecting it as a load.

The controls for shift and throttle are what most people would consider critical. As a result, it would be nice if they had a back up power supply. This device does that by selecting the highest voltage of either of the two power supplies (batteries) that are connected to it, thats it. Nothing more. The batteries themselves are never connected together.
This way the engine controls hopefully have a separate, secondary, workable voltage source.

Even though your engine's throttle and your gear's shift selection is done by cable at the engine/gears, the fact that you have this device tells me that these cables only go to a box about 10" square and 8" thick, likely in the ER, which is only wired to your controls at the helm(s). Inside the box are the motors, cable connection hardware and controls that actually pull/push the cable. You are almost "fly by wire" as your actions at the helm only produce an electrical signal. No control cable is pushed by the helm levers.

This device is a diode based selector and as a result the voltage drop through the device is said to be 0.35 to 0.45 Volts depending on load. If you are measuring 0.6 volts, make sure no voltage drop from the conductors is included.

The device, although branded ZF is likely made by Newmar out of Newport Beach CA. which uses as a motto "A Mission Critical Electronics Brand." How fitting!

Here is a link to their info. on the product. Doesn't it look similar? Stickers are easy to make.
Newmar generally mades good stuff, albeit you won't find it on your phone.

Automatic Power Selector | 12V DC | 24V DC | 48V DC | 70 Amps to 160 Amps | Mobile Mount | Newmar Powering the Network

Automatic Power Selector by Newmar Powering the Network: 12V DC, 24V DC and 48V DC, 70 Amps to 160 Amps. The Automatic Power Selector (APS) is a solid state device which enables installation of a seamless, redundant power system for critical electronic loads. It selects the higher voltage of two...

www.poweringthenetwork.com

If it was me, I would confirm what powers it (both feeds) and what are the loads. Once I'm happy with that, I would keep it as it provides a useful service.

I’ll second all of the above.

Engine control systems often have provision for dual power inputs so they keep running even if one power source fails. Classes commercial boats require this, but not recreational boats. When building my boat I went to some extent to make sure all these dual power supplies we actually connected and used. I think it’s even MORE important to have if one of you banks is LFP with a BMS disconnect possibility

 

[O C Diver]

My vote would be to disconnect the output wire and see what doesn't work. Then decide whether you think it needs protection. Do this at the dock .

Ted

 

[dhays]

I would get rid of it for 2 reasons;

1) It drops half a volt which is way too high for a switch.

I agree that half a volt is a lot. That is why I was wondering if it was failing as I can't imagine accepting that much of a voltage loss.

2) The max load is 70 amps. Seventy amps? You must be joking. Probably another reason it drops half a volt.

The amps aren't an issue here. As near as I can tell, it isn't handling the loads, but the circuit it is controlling only powers up the Blue Seas solenoids that control engine start, genset start, fore and aft thrusters, windlass and crane. Each of those solenoids only draws 1/8th amp. So if all 6 are activated, that is still under one amp. In fact, both of the source wires and the load wire are protected by 10 amp fuses. I've tapped into that circuit for two other relays. One draws 33mA and the other draws about 150mA. So even if all are activated, that is still under an amp.

 

[Portage_Bay]

Assuming Luna is correct and this is a diode based device that's where the 1/2 volt is going. Diodes to that.

It sounds like you know what it powers. Those sound to me like systems I would not want to loose. I'd keep the device and let it do it's job.

 

[dhays]

My vote would be to disconnect the output wire and see what doesn't work. Then decide whether you think it needs protection. Do this at the dock .

Find out what it powers. Disconnect the load side and see what doesn't work.

What do your engines require to run? An electric fuel solenoid in an energize to run system? Any electronic engine controls, not throttle and shift.

It may also be powering the engine electronics. I assume you have a common rail engine, it will stop instantly without 12V power.

I think all it powers are the solenoids I mentioned to @Delta Riverat . It is only fused at 10amps, so the most it could power would be a relay or solenoid. I will check though to make sure that it isn't controlling any engine components. There aren't any electronic controls in the system.

Ignore everything I wrote, the cables threw me.

Indeed there is a ZF Mathers control box that takes cable inputs and uses servo motors to do cable outputs. Only 3 grand each.

That is what this APS is used for most of the time I believe. However, there are no ZF Mathers controls on the boat. I am positive on this as I completely took apart and relubricated the cable system a few years ago. I checked the controls from both helm positions all the way back to the engine.

The Automatic Power Selector likely does not feed the house circuit, nor are the thrusters likely connected to it as a load.

It does what its name implies, selects the higher of any two connected power sources (they don't have to be batteries) to power whatever you connect to it as a load. The load is often just the ZF Microcommander controls, nothing else, unless you also deem it critical (your VHF?) by connecting it as a load.

This device is a diode based selector and as a result the voltage drop through the device is said to be 0.35 to 0.45 Volts depending on load. If you are measuring 0.6 volts, make sure no voltage drop from the conductors is included.

The device, although branded ZF is likely made by Newmar out of Newport Beach CA. which uses as a motto "A Mission Critical Electronics Brand." How fitting!

Here is a link to their info. on the product. Doesn't it look similar? Stickers are easy to make.
Newmar generally mades good stuff, albeit you won't find it on your phone.

Automatic Power Selector | 12V DC | 24V DC | 48V DC | 70 Amps to 160 Amps | Mobile Mount | Newmar Powering the Network

Automatic Power Selector by Newmar Powering the Network: 12V DC, 24V DC and 48V DC, 70 Amps to 160 Amps. The Automatic Power Selector (APS) is a solid state device which enables installation of a seamless, redundant power system for critical electronic loads. It selects the higher voltage of two...

www.poweringthenetwork.com

If it was me, I would confirm what powers it (both feeds) and what are the loads. Once I'm happy with that, I would keep it as it provides a useful service.

That is a great explanation of how the device works. Thanks. I will double check the voltage drop. If it is really around .4v then I will assume the device is working well.

There are 10 amp Class H or K fuses there now (not sure which, I'll have to check). I really don't like the fuse holders as they use a screw down clamp connecter on the 10 AWG wire. I would much prefer a ring terminal connection. I will check to see exactly what type of fuse are used. Unless there is a specific reason for that type of fuse, I'd prefer to change it to something with more secure wire connections.

 

[Delta Riverat]

I think I got it now, it's a diode combiner as opposed to an isolator. 2 diodes forward direction to the middle. If one bank is low, the other automatically shares. But you wouldn't know you had a battery problem either.

I think I'd prefer a switch.