Submitted by DonHester on Sat, 08/15/2015 - 18:52.
Just a flip and a relay and on comes the light-
Low voltage lighting and control systems.
Wenatchee Home Inspections
It was to be the new rage. A supposed “economical” system to control your lighting circuits. You can wire any number of switches, photo sensors, timers and other devices to a relay that now can control any lighting fixture(s) or electrical loads that were controlled by that relays. The wiring from the switches and devices are low voltage (typically 24 to 30v) so no need for heavier cabling and conduits etc…
GE introduced its low-voltage remote-control relay system in the 1950s as an alternative to conventional line-voltage switch wiring, mainly for lighting. Touch Plate goes back to the mid to late 1940’s. You most likely will see these in older high end homes and commercial/industrial applications.
These systems are still out there to be found and as home inspectors, I find these types of systems actually kind of cool and very interesting.
I have found that most of these systems often are in need of repairs and/or replacement due to age and that often the owners and/or tenants are not even aware of how these systems actually function.
From GE-
“The low-voltage switching platform consists of relay panels which are typically mounted in the electrical closet. Each lighting load to be controlled is wired through a relay. The relays, in turn, are connected to manual switches with low-voltage wires.
The resulting switching platform has a number of benefits:
Any number of switches can control a single relay.
This makes it possible to control the lighting from any number of locations, including a central switching console.
The status of each lighting load can be annunciated.
This makes remote switching of lighting circuits code-compliant and practical.
Relays can be grouped for common control. This provides a low cost, reconfigurable, multi-pole contactor function.
Low-voltage wiring reduces wiring cost by eliminating the need for expensive conduit. This is especially important in long switch runs.”
(Sierra Switch)
From Pass & Seymour/Legrand-
“The low-voltage system differs from conventional switch wiring by actuating relays through the use of momentary contact switches. This type of switching utilizes a transformer to provide safe low voltage current to control line voltage circuits. The wiring of lights and other electrical loads is installed in the conventional manner.”
When find these systems during the home inspection you should find the control panel or relay station depending on the complexity of the system. These will typically have a 24v to 30v transformer by them to provide power for low voltage switching.
Here is a low voltage control panel (GE/Bryant) that needs a bit of love, and it not safe as it sits. It seems messes follow low voltage systems be it lighting or communication.
Some of the other manufacturers of these systems were Bryant, Remcon,Touch Plate and Sierra. Pass & Seymour purchased Sierra Electric when they went out of business. Typically the relays and other components are not compatible with each other. Bryant was using a wiring system based on the same transformers and solenoid relays used in the GE systems, so parts in this series are compatible with GE lighting systems.
Here is a some examples of Bryant switches.
(Bryant Switches)
Your biggest obstacle will be finding electricians that have knowledge and comfort working on these systems and then there are cost of parts and sourcing of materials but I found a few sites that provide supplies.
From Touch Plate-
“We support all of our products, dating back to 1946, as well as other low voltage systems, such as GE and Remcon.”
“An investment in knowledge pays the best interest.”
Benjamin Franklin
NCW Home Inspections, LLC is a Licensed Washington State Home Inspection service located in Wenatchee Washington serving Chelan County, Douglas County, Kittitas County, Okanogan County and Grant County Washington and the cities of Wenatchee, Leavenworth, Cashmere, Oroville, Cle Elum, East Wenatchee, Quincy and many more…
Your Wenatchee and Chelan Professional Real Estate, Home and Structural Pest Inspection Service
Instructor- Fundamentals of Home Inspection- Bellingham Technical College