Brian North Introduction

(moderated) New members: Say Hello here! News and Events from LumenCache as well as new product announcements.
Post Reply
bn
Posts: 3
Joined: Wed Nov 11, 2020 10:46 pm

Brian North Introduction

Post by bn »

Good day from Kimberley, British Columbia.

My name is Brian North and I've installed LumenCache in the high performance house that my wife and I took possession of in July of 2020. I first became aware of LumenCache and the idea of low voltage lighting while sitting around a camp fire with a friend who had started his own electrical contracting business. My background being in telecom and networking, I expressed interest in using PoE for some of the lights going into my new house. His recommendation was to investigate low voltage DC lighting, as he identified it as being a disruption to the status quo of commercial lighting in the near future. After a few hours of searching online I came across LumenCache, reached out to the sales contacts and was put in touch with Clint of Hartman Electric. It took about 5 seconds before I was sold on the idea, although some of the concepts required additional processing time. The fact that I could pull my own wire, crimp an RJ-45 on the end, plug it in AND it would work was all I needed to convince me that this was the right direction to go in.

Reducing the energy demand of the house also contributed to the decision to install LumenCache, as our design gravitated more and more towards Passive House standards. My main goal for the house was to live in a building that didn't need to burn something in order to be livable. A risky endeavor for a small mountain town where every house has 1 or 2 wood burning fireplaces AND a natural gas furnace. But every decision made during the design process was done so in a logical, iterative fashion; reduce or eliminate X then Y doesn't need to be as big and then more can be spent on Z which has a positive impact on... and on and on.

There were certainly some headaches along the way... Convincing the general contractor and electrical contractors that yes, the system was safe and I wasn't re-inventing the wheel, and that standard light fixtures could be modified for use with LumenCache, were just a couple of the human related challenges. An unexpected hardware failure of the original power supply (2 days before the occupancy inspection) was another.

The system I have installed is a a modestly sized 4 L2-PDM powered by a 480W 48V Weidmuller PSU, backed up by 35Ah of batteries (4x12V). The batteries were a life saver as they allowed me to run the system and pass the inspection before the replacement PSU arrived, FOR 3 DAYS! It helped that this was mid July and the sun was up from 5:30 AM to 10 PM... On my roof is a grid-tied 10kW PV array which has been oversized to produce slightly more energy (12.78MWh) than what the estimated current demand is (11MWh). I chose not to dedicate any PV panels to LumenCache with the reasoning that IF the batteries became fully charged and there was still sun shining on the panels, the potential energy that could have been generated by those panels would be lost. Therefore the AC PSU was chosen instead of a PV battery charger, but it sure is nice to have every single light in the house running off of a single 20A breaker (which is also powering the 1500VA UPS that's backing up the network).

The other components of my LumenCache system are:
  • 64 4W 2" LC recessed lights
  • 40 6W 24V DC bulbs (in various fixtures)
  • 1 Bathroom fan (for a cold room fed by 100' of earth tube)
  • 1 Dual outdoor floodlight(in various fixtures)
The system was sized to support an additional:
  • 14 USB
  • 4 2'x4' ceiling panels (for the garage)
  • And with some luck, all of the Christmas lights that my wife will want in the future.
... and if she wants more lights, then I'll just have to expand the system..

User avatar
dc
Posts: 157
Joined: Thu Dec 20, 2012 4:23 am
Contact:

Re: Brian North Introduction

Post by dc »

Great introduction Brian! I heard about your project from Clint and looking forward to seeing photos during and after.

MTBF of the power supplies we spec are more than a human lifetime, and I think the Weidmuller are similar. But the batteries lasting 3 days and getting you through the inspection is classic!

Can you get 48V from your PV system batteries directly and avoid the AC altogether?

bn
Posts: 3
Joined: Wed Nov 11, 2020 10:46 pm

Re: Brian North Introduction

Post by bn »

Yes the failure of the PSU was much sooner than expected, probably 26 hours of run time instead of >500,000. Taking a measurement of the PSU output would start at 0 VDC and then slowly climb before peaking at 1.94 V, even though the output was dialed up to 52 V. No noticeable buzzing, odor, or any indicator light. I was in the room with my back turned to the unit when it failed, just a quiet 'click' and it was dead. From that experience alone I am now an advocate for having a battery system to complement the generation (or consumption) system. Unfortunately I don't have such a system for the entire house, my PV inverter follows standards similar to California (anti-islanding) and therefore shuts down when the grid goes down. Although I'm certainly keen on implementing a battery storage system in the future.

And I'm very keen on adding some thought to the source of the energy that is in the LC batteries. I have six 5'x7' windows on the South side, it's hardly ever dark in here except for at night, when the sun doesn't shine and all of my energy demand is met from the grid. I plan to add a simple switch in front of the PSU to easily turn it off at night and on in the morning. That will be automated in the future based on a few variables, such as battery voltage, time of day, is the inverter producing power, etc.

User avatar
dc
Posts: 157
Joined: Thu Dec 20, 2012 4:23 am
Contact:

Re: Brian North Introduction

Post by dc »

The Iota chargers did the same. They needed a crowbar circuit and could get stuck on current overload for a split second, then shut down, then trip, etc, thousands of times per second. Resulting in 1-2V and crushing current :-D. The Meanwell HEP-600 and 1000 are awesome. No fans too!

Advanced motion sensors are coming and a TP/switch with proximity detection.

Post Reply