Paneltronics Distribution panels...good?

[er9]

was wondering if anyone had any experience with the quality of their panels. they look like a top notch company and have some really nice pre-wired panels. like to try and get some feedback first though before purchasing anything from them.

[Bycrick]

I looked at their line several years ago. Decided not to, mostly because of some mechanical considerations on the boat. Thus, I never actually saw a real panel. The one thing that bothered me is that their DC meters are awful. 2% accuracy? Analog meters are also harder to read accurately than digital ones. The voltmeter reads panel voltage not battery voltage. The amp meter reads panel current not battery current. So you’ll still need a battery monitor like the Victron 712. The AC meters, even the analog ones, were OK.

[Singularity]

Sharing some thoughts as I will be replacing my panel soon and have looked at the different common manufacturers...

-For DC panels, my take is that the on-panel volt meters aren't precise enough for LFP where, even if LFP isn't installed now...if one has a separate accurate battery voltage meter/smart meter adjacent to the DC panel, consider saving money and not getting a panel with an on-board meter.

-Big tangent: Are you installing new conductor wire through the boat? Home runs (single wire from panel to end appliance)? How will you size your breakers?

Based on reading many previous threads here...it seems that many people size breakers to protect the conductor wire while neglecting, perhaps, to install an inline fuse downstream of the circuit breaker to protect that actual appliance/device (if/when the device requires lower amp protection). Boats wired in this way may have good looking breakers that, because oversized, maybe are not sufficiently providing complete circuit protection.

As I've gone from 12v to 24v, and in replacing conductor wire with oversized wire (cheap insurance to me), this finds some circuits requiring inline fuses as circuit breakers tend to be in amp units that are too-small or too-large for what the end device actually needs. And each inline fuse downstream of the breaker is a point of potential corrosion failure, +/- buried behind structure if the fuse blows.

The point of mentioning all this is to suggest considering just using a blade-type fuse panel for the DC circuits. This allows one to more precisely select, at the panel itself, appropriate circuit protection (particularly if home runs are used).

This fuse business is apparently controversial here, maybe seen a agricultural/unrefined, but I'd mention that at least in the homebuilt airplane community people who are not poor are going back to fuses for very logical reasons that make just as much (if not more) sense on a boat. Where "glows when blows" fuses are now available, and the bilge pump can earn a discrete inexpensive breaker panel, I'm looking hard at the Axion products from UK as I can't find a US-based company providing similar. Doesn't hurt that they are inexpensive (maybe the delta in cost going to oversized wire).
https://www.axoncontrol.co.uk/dc-dis...product_id=342

[Bycrick]

Singularity talks about "on panel meters" not being accurate enough for LFP. He’s "half-right:." They’re not good enough for battery voltage. At all. Not LFP, not lead-acid. Even if they meet their specs of 2%.

Analog meters are rated at % of full-scale. So the meter has a 20 volt maximum. +/- 2% means +/- 0.4 volts. That means if the meter reads 12.4 volts, the actual voltage could be 12.0 to 12.8 volts. At that, you’re better off with an idiot light.

Even if they were good digital meters, they’re measuring the panel voltage, not the battery voltage. And a digital meter that reads to one decimal place isn’t going to be very precise, unless they’ve used more expensive circuits to actually measure to two decimal digits and then round off the display. The usual one-decimal-digit meter can’t tell the difference between one count in the last digit. So it reads 12..4 but the voltage is somewhere between 12.3 and 12.5. That difference is about 25% of capacity.

[smac999]

They come factory on many boats. Never bought one though. I use bluesea.

For the volt meter. Just extend the cable to the battery. Any panel you buy is Likly setup to read from the panel.

[Lake-Effect]

Originally Posted by Singularity

Sharing some thoughts as I will be replacing my panel soon and have looked at the different common manufacturers...

-For DC panels, my take is that the on-panel volt meters aren't precise enough for LFP where, even if LFP isn't installed now...if one has a separate accurate battery voltage meter/smart meter adjacent to the DC panel, consider saving money and not getting a panel with an on-board meter.

Last week I did a bit of work on a new friend's boat electrical system. His panel DC meter (expanded scale - 8 to 16v) had a shorted zener diode (the thing that eats the first 8 volts). After replacing that diode, I aligned the meter movement to be within 0.1v when the voltage is 12.5v.

So, the stock in-panel analog meters aren't necessarily useless or inaccurate. They're nice to have as a quick check, and if all your DC breakers or loads are off, then you're essentially reading the battery voltage accurately. I would still also put in a battery monitoring system with low- and over-voltage alarms.

Based on reading many previous threads here...it seems that many people size breakers to protect the conductor wire while neglecting, perhaps, to install an inline fuse downstream of the circuit breaker to protect that actual appliance/device (if/when the device requires lower amp protection). Boats wired in this way may have good looking breakers that, because oversized, maybe are not sufficiently providing complete circuit protection

The first and most important job of breakers and fuses is to protect wiring; a short in an unprotected wire run could lead to a fire.

The protection of individual devices, if advisable, should be done right at the device - ideally incorporated into the device, or an inline fuse just before the device. In the case of home-run wiring for each device, it could be logical to use a lower value fuse at the panel. But it's still nice to have upstream breakers protecting logical blocks (eg cabin lighting, nav lighting, nav instruments, etc)

As I've gone from 12v to 24v, and in replacing conductor wire with oversized wire (cheap insurance to me), this finds some circuits requiring inline fuses as circuit breakers tend to be in amp units that are too-small or too-large for what the end device actually needs. And each inline fuse downstream of the breaker is a point of potential corrosion failure, +/- buried behind structure if the fuse blows.

The point of mentioning all this is to suggest considering just using a blade-type fuse panel for the DC circuits. This allows one to more precisely select, at the panel itself, appropriate circuit protection (particularly if home runs are used).

Fuses can be more precise than breakers, and they blow almost instantaneously. But you have to make sure you always have enough spares on hand. My feeling is that DC breakers do a good enough job of protecting wiring from shorts.

There are ABYC charts for sizing wire runs. These already have a small safety factor built-in, so as long as a circuit's wiring has been sized correctly, and the circuit is protected by the right-sized breaker or fuse, there isn't really much benefit to upsizing the wire gauge, in most cases.

[Bycrick]

As Lake Effect said, you CAN adjust an analog voltmeter to read within +/- 0.1 volts. Will they do that at the meter factory? Zener diodes are inherently non-linear devices, so the fact that the meter is right at say 12volts doesn’t tell you if it’s accurate at 15 volts. Will they tell you something? Yes, but as others have said, you’ll need a good meter reading voltage at the battery. WRT the stated accuracy of +/- 2%, note that the Victron 700 monitors were rated at +/- 0.3%. And +/- 0.1 volts is the difference between about 50% SOC and 75%.

[er9]

Originally Posted by Singularity

Sharing some thoughts as I will be replacing my panel soon and have looked at the different common manufacturers...

-For DC panels, my take is that the on-panel volt meters aren't precise enough for LFP where, even if LFP isn't installed now...if one has a separate accurate battery voltage meter/smart meter adjacent to the DC panel, consider saving money and not getting a panel with an on-board meter.

Yeah i'm not a big fan of on panel meters. i have one now on my panel and it is horribly innacurate. i have an SG-200 (not installed yet) and was planning on getting another, one for each bank and skipping the 'on panel' metering altogether. i'm not exactly saving money as the SG-200 is expensive but i trust they will be about as accurate a reading as i can get.

-Big tangent: Are you installing new conductor wire through the boat? Home runs (single wire from panel to end appliance)? How will you size your breakers?

Yes most of it will have its own fuse/breaker/on-off switch. not all devices though. i will logically group things such as lighting, nav lights etc...AC breaker size was something i'm just beggining to think about. i have to admit its a bit of a fuzzy grey area so i need as much input as possible. for the AC side i was simply going to size each breaker to the max wattage of the appliance. for outlets, the max wattage of what im using now is 1500 watts for my small heater so was going to size outlet breakers @ 15AMPs. each oulet will have its own switch/breaker. my boats set up that way now and i really like it however im open to better ideas.

Based on reading many previous threads here...it seems that many people size breakers to protect the conductor wire while neglecting, perhaps, to install an inline fuse downstream of the circuit breaker to protect that actual appliance/device (if/when the device requires lower amp protection). Boats wired in this way may have good looking breakers that, because oversized, maybe are not sufficiently providing complete circuit protection.

Since i plan to put everything on its own switch i hope to avoid that but definately something im aware of.

As I've gone from 12v to 24v, and in replacing conductor wire with oversized wire (cheap insurance to me), this finds some circuits requiring inline fuses as circuit breakers tend to be in amp units that are too-small or too-large for what the end device actually needs. And each inline fuse downstream of the breaker is a point of potential corrosion failure, +/- buried behind structure if the fuse blows.

The point of mentioning all this is to suggest considering just using a blade-type fuse panel for the DC circuits. This allows one to more precisely select, at the panel itself, appropriate circuit protection (particularly if home runs are used).

I was planning on having a fuse bus at some location, probably near the main +bus bar i could tap into for more selective fusing on the DC circuit. Blue Sea has a nice one that accomodated a nice assortment of fuse sizes. not sure if thats what your getting at though.

This fuse business is apparently controversial here, maybe seen a agricultural/unrefined, but I'd mention that at least in the homebuilt airplane community people who are not poor are going back to fuses for very logical reasons that make just as much (if not more) sense on a boat. Where "glows when blows" fuses are now available, and the bilge pump can earn a discrete inexpensive breaker panel, I'm looking hard at the Axion products from UK as I can't find a US-based company providing similar. Doesn't hurt that they are inexpensive (maybe the delta in cost going to oversized wire).
https://www.axoncontrol.co.uk/dc-dis...product_id=342

................................

[er9]

Originally Posted by Bycrick

Singularity talks about "on panel meters" not being accurate enough for LFP. He’s "half-right:." They’re not good enough for battery voltage. At all. Not LFP, not lead-acid. Even if they meet their specs of 2%.

Analog meters are rated at % of full-scale. So the meter has a 20 volt maximum. +/- 2% means +/- 0.4 volts. That means if the meter reads 12.4 volts, the actual voltage could be 12.0 to 12.8 volts. At that, you’re better off with an idiot light.

Even if they were good digital meters, they’re measuring the panel voltage, not the battery voltage. And a digital meter that reads to one decimal place isn’t going to be very precise, unless they’ve used more expensive circuits to actually measure to two decimal digits and then round off the display. The usual one-decimal-digit meter can’t tell the difference between one count in the last digit. So it reads 12..4 but the voltage is somewhere between 12.3 and 12.5. That difference is about 25% of capacity.

yeah thats been my experience as well. i tested my house battery last night, it was at 12.8ish volts and my meter was showing under 12.2

[flightlead404]

Originally Posted by Singularity

.it seems that many people size breakers to protect the conductor wire while neglecting, perhaps, to install an inline fuse downstream of the circuit breaker to protect that actual appliance/device (if/when the device requires lower amp protection). Boats wired in this way may have good looking breakers that, because oversized, maybe are not sufficiently providing complete circuit protection.

I haven't done any boat systems, but I've done plenty of airplanes from the ground up (all 12v).

Circuit interrupting devices (fuses, breakers, etc) are there to protect the wire, not the device. They are to prevent over current situations such as shorts to ground where the wire would heat up and cause a fire hazard. FWIW some insulation when heated or burned emit toxic fumes, these wires should never be used in enclosed spaces (boats, airplanes. I use only mil-spec tefzel or equivalent on any airplanes and cars I do.

Wires should be sized based on maximum anticipated load and the calculated voltage drop over the distance run x 2 (there and back again). There is also an additional safety factor to be calculated in when the wire is in a bundle vs in "free air". Plenty of resources online to figure all this out for you.

Adding an additional circuit interrupting device near the load to protect it adds a layer of complexity and an additional failure point that could possibly be catastrophic depending on what the load(s) are and when it fails (always at the worst possible time).

But why add anything near the load?
1) All modern devices are fused internally anyway
2) If there's a short its in the wire before it gets to the device so there's nothing to protect the device from
3) If the device itself is the problem the additional fuse doesn't help
4) If the ground side shorts, well its going to ground anyway
5) If the supply side is grossly oversized, just use a lower rated circuit interrupting device

Am I missing something?

[Lake-Effect]

Originally Posted by Bycrick

Analog meters are rated at % of full-scale. So the meter has a 20 volt maximum. +/- 2% means +/- 0.4 volts. That means if the meter reads 12.4 volts, the actual voltage could be 12.0 to 12.8 volts. At that, you’re better off with an idiot light.

It's not true that just because the rated accuracy at full-scale is +/- 2% (resulting in +/- 0.4v in your example), that the reading will be unreliable by that amount, or that the +/- 0.4v uncertainty applies all the way down the scale.

There's a difference between accuracy and precision. Accuracy is how close a given device agrees with a known good standard - eg a 'certified' 20.00v source. Precision is how tightly a given voltage provides the same reading. So our +/-2% accurate meter may read 19.6v from a 20.00v source, but if it always reads 19.6v from that source, then you can say that it's a reasonably precise meter.

Your meter may be out by +/-2% of full scale (accuracy) but it's usually more precise than the same 2%, and once you know that (by comparing with a decent DMM), then you'll have a mental correction factor (eg when it reads 12.6v it's actually 12.7v), or you can even tweak the meter (series resistance and/or movement) to be more accurate at the point of greatest interest (~12.5v).

Originally Posted by er9

yeah thats been my experience as well. i tested my house battery last night, it was at 12.8ish volts and my meter was showing under 12.2

This is most likely because of voltage drop between the batteries and the panel. If you switch off all DC loads, what does the panel DC voltmeter read?

This observed drop is also useful; seeing the different drops as loads are switched on is good information. If you're seeing a significant drop when loads are switched on, it could point to a problem in the wiring between the batteries and the panel, or that your batteries are starting to develop higher internal resistance, or that a battery terminal is a bit loose... etc.

[er9]

Originally Posted by Lake-Effect

This is most likely because of voltage drop between the batteries and the panel. If you switch off all DC loads, what does the panel DC voltmeter read?

This observed drop is also useful; seeing the different drops as loads are switched on is good information. If you're seeing a significant drop when loads are switched on, it could point to a problem in the wiring between the batteries and the panel, or that your batteries are starting to develop higher internal resistance, or that a battery terminal is a bit loose... etc.

thanks, good question. i will have to check this weekend when im at the boat.

[Singularity]

Originally Posted by flightlead404

...Circuit interrupting devices (fuses, breakers, etc) are there to protect the wire, not the device....

This is often repeated but is not correct/complete as stated, while your last statement

If the supply side is grossly oversized, just use a lower rated circuit interrupting device

closes the loop.

1) All modern devices are fused internally anyway

Herein I suggest is the rub. Devices are protected to the amp level they say they're protected to*.

Say you have an old strobe light installed on a circuit with a 15A breaker. You then change to an efficient LED whose manufacturer calls for protection not to exceed 4A. If you merely swap the light units, then after the fact the wire leading to the light is fully protected by its 15A breaker. But we know we have a problem. Protecting the wire isn't enough. So if we swap a 5A breaker is this 'close enough'? The device manufacturer didn't think so, they said 4A...in turn we can postulate how/why the mfg came up with the 4A number (*e.g. if 4A is really conservative to make lawyers happy).

So both the conductor and unit have to be protected, we all agree. What I contend is probably too common and poor practice is to have a larger breaker installed because...breakers only come in the sizes they come in (and/or ppl have a brain fart and figure 5A is better than 4A). This really comes to a head when you sit down and try to figure out which amp breakers you need vs what's available, where bladed fuses of appropriate size are sourced locally all over the place.

FWIW Nigel Calder makes the point on page 237 of his mechanical/electrical manual that inline fuses are needed depending on what current the upstream device interrupts at. Agreed as stated above that inline fuses next to the load are not ideal, part of the rational to use appropriate sized fuses at the panel, where/when 'appropriately sized' can be hard to do with breaker offerings.

Regardless, OP is on top of the "how am I going to run those loads through which breakers" problem.

I otherwise don't mean to advocate fuses for AC circuits.

[Lake-Effect]

Originally Posted by Singularity

So both the conductor and unit have to be protected, we all agree. What I contend is probably too common and poor practice is to have a larger breaker installed because...breakers only come in the sizes they come in (and/or ppl have a brain fart and figure 5A is better than 4A). This really comes to a head when you sit down and try to figure out which amp breakers you need vs what's available, where bladed fuses of appropriate size are sourced locally all over the place.

The difference between a 4 amp breaker/fuse and a 5 amp breaker/fuse, in terms of protecting a wire OR a device from shorts, is just about negligable. The manufacturer specs a 4 amp fuse because they know that the reasonable normal peak draw of their device is under 3 amps (or some such arbitrary factor is employed). Their device won't ever normally draw >= 4A, so that's a reasonable choice. Any device failure that would blow a 4A fuse/breaker is 90% or more likely to blow a 5A fuse/breaker too.

When sizing for branch circuits, it's quite reasonable to work in 5 or 10A increments. In any panel, house or boat, the breaker/fuse protects the wire.

If the power wiring of every device that needs fuse protection is home-run to a fuse panel somewhere, then sure you can choose a lower fuse value there to match each device. But I think that's overkill, and inflexible. I would be more likely to have, for example, a DC breaker for the nav station electronics (say, 10 or 15A, depending on total equipt draw) which feeds a small fuse panel right at the nav station, and that "sub-panel" or block protects and feeds individual devices. More efficient use of wire, and much easier to add/remove devices at the nav station. All with the proper protection.

Also remember that the more wires you run, the more work, the more connections, the more places for a questionable connection or other issue to crop up...

FWIW Nigel Calder makes the point on page 237 of his mechanical/electrical manual that inline fuses are needed depending on what current the upstream device interrupts at. Agreed as stated above that inline fuses next to the load are not ideal...

(which edition? That page doesn't match up in my 3rd edition copy) No... I would consider having the fuse with the device to be ideal. When troubleshooting a device, the fuse is right there with it to check.

A lot of this is more personal preference than better/worse, as long as the usual standards and rules are always adhered to.

I think careful workmanship and good quality parts, connectors, crimps etc are more important overall. Rate the wires properly, run them carefully, alowing slack at each end, NEVER bury a splice or connection so that it can't be reached easily... these practices will have greater bearing on the long-term performance of a rewiring.

[flightlead404]

Originally Posted by Singularity

This is often repeated but is not correct/complete as stated, while your last statement
closes the loop.
Herein I suggest is the rub. Devices are protected to the amp level they say they're protected to*.

Say you have an old strobe light installed on a circuit with a 15A breaker. You then change to an efficient LED whose manufacturer calls for protection not to exceed 4A. If you merely swap the light units, then after the fact the wire leading to the light is fully protected by its 15A breaker. But we know we have a problem. Protecting the wire isn't enough. So if we swap a 5A breaker is this 'close enough'? The device manufacturer didn't think so, they said 4A...in turn we can postulate how/why the mfg came up with the 4A number (*e.g. if 4A is really conservative to make lawyers happy).

So both the conductor and unit have to be protected, we all agree. What I contend is probably too common and poor practice is to have a larger breaker installed because...breakers only come in the sizes they come in (and/or ppl have a brain fart and figure 5A is better than 4A). This really comes to a head when you sit down and try to figure out which amp breakers you need vs what's available, where bladed fuses of appropriate size are sourced locally all over the place.

FWIW Nigel Calder makes the point on page 237 of his mechanical/electrical manual that inline fuses are needed depending on what current the upstream device interrupts at. Agreed as stated above that inline fuses next to the load are not ideal, part of the rational to use appropriate sized fuses at the panel, where/when 'appropriately sized' can be hard to do with breaker offerings.

Regardless, OP is on top of the "how am I going to run those loads through which breakers" problem.

I otherwise don't mean to advocate fuses for AC circuits.

agreed. My comments were mostly from the point of designing the system not retrofitting a new device to an existing system. One should always check to make sure first, draw is not going to exceed design, and second that a sanely sized (and type) interrupter is used for the new device.

no one mentioned them here, but I've seen a lot of systems designed with "switch-breakers". These are devices with a toggle switch that has a breaker built into them. The old Potter-Brumfield WG series is a good example. The thinking is a reduction in part count increases MTBF. The Potter ones are now made by Tyco and turn out to be a worse solution. There seems to be a fairly high failure rate after a few 100 to 1000's of actuations, especially in high vibration environments. Mostly failing open but I've heard of them over heating as well.

I've gone to Carling G Series switches and Bussman ATC fuse buss blocks.