ART TEC solar - Controller Specifications

Specifications

Features	DTC-1	DTC-AT	DTC-D
Features	simple affordable	adjustable differential and max temp	available in enclosed or electric box cover versions
Retail price	$90	$120	$200
Operating Voltage	3-32	3-32	3-30
Solar panel (or battery) nominal voltage	12 or 24	12 or 24	12
Pump voltage	12 or 24	12 or 24	12 or 24
Uses standard 10K thermistor temperature sensors Order separately - 2 required per controller
Back lighted LCD	N/A	N/A
Pump control: ON/AUTO/OFF	internal switch	internal switch	selectable modes
Adjustable differential		5 to 35F	4-32F
Adjustable max temperature shut down senses storage temperature		80-200F	100-200F
Over temperature warning for storage		red indicator on front panel	audible alarm
Over temperature pump control for heat dump (option)
Freeze protection activates pump below set point of 1 to 36F (requires battery backup)
Audible freeze warning if collector is below 34F
Displays temperatures in F or C
Displays historic high and low temperatures for collector and storage (resettable)
Internal battery maintains temperature/status display 24/7	N/A	N/A
Pump running green LED indicator on front panel
Switches up to 6 Amps (72 Watts) Or higher with external relays - see Accessories
Replaceable 6 amp 3AG type fuse inside
Built in surge protection protects electronic motors
Ambient Operating Temperature of controller -40 - 185F (-40 - 85C)
Dimensions (not including mounting ears)	2.5 X 3.5 X 1.25" (65 X 88 X 42mm)	2.5 X 4.75 X 1.25" (65 X 120 X 42mm)	2.5 X 4.75 X 1.25" (65 X 120 X 42mm)
5 year limited warranty

MANUALS

DTC-1 DTC-AT DTC-D

REAL TIME PERFORMANCE STATISTICS FOR 2 SYSTEMS THAT USE THE DTC-D CONTROLLER

BUILDING HEAT

click image to see real-time data DOMESTIC HOT WATER

click image to see real-time data

Why solar power and not AC to run your circulation pump?
To quote Chuck Marken's Article "Pick the Right Pump: Choosing a Circulator for Solar Hot Water Systems" in Home Power magazine (issue #121):

One way to approach the DC and AC pump choice is to examine relative system efficiencies. The efficiency of some heating systems is rated by the relationship of the amount of energy output to the energy input. If you have a system that produces a certain amount of heat with half the equivalent electrical input, the “coefficient of performance” (COP) is 2. Produce four times as much hot water as the amount of energy input from electricity and the COP is 4. We can use this same methodology in evaluating the efficiency of SHW pumps. Using a utility-powered AC pump for your solar water heating system will give you a COP between 12 and 25, and this is an excellent value compared to electric water heaters, which have a COP of 1.

But the COP will never be as good as a DC PV-powered SHW system. DC hot water circulation pumps can have a higher COP than AC pumps because there is no traditional energy input if a PV module powers the system. If you use a solar-electric module to power the pump, your COP is infinite—you’re not adding any input energy. The sun provides it all, and you get something for nothing after the initial investment. PV-powered systems are also immune to utility outages. This is a big plus with antifreeze systems, since the collectors can overheat on sunny days if the pump stops operating due to a power failure. An overheated collector can actuate the pressure-relief valve, which will make it necessary to recharge the system with antifreeze solution. In some cases, the overheating can be so severe that the antifreeze solution will be compromised to the point of needing replacement.

Some unsolicited testimonials:
"Working great! One of the best upgrades I've done to my system."
"Works great! I recommend you to all my associates."
"Very clear and easy. Lots of extra good information was contained in the manual"
"The manual was very self explaniatory to me. We are using the controller for a wood heated hot water set up and it works perfect."
"This is a terrific product and I am VERY satisfied. Even for me as a MD it was easy to install. Good documentation, thank you very much."
"This was a fantastic purchase. For a decade I have been happily hearing my pump working on sunny winter days but ended each day with a tank at 60ºF. I was just pumping cold glycol around before and after midday. This winter the family has been all solar on many days and the tank temperature is never lower than 85º, which I then only have to raise to 108º. My only suggestion is that the small screwdowns for the wires didn't grab the small size I was using (twisted pair from Radio Shack) and I ended up crossing over to 14 GA house wire before terminating. Great product. Thanks for offering it."
"Works reliably, glad I got it."
"Works great, easy to install, manual explains things well.
PS I hope you are doing a great with your business. We need more solar hot water units in place"
"I'm using your DTC-1 (built like a tank - been through every operating condition imaginable (-30 to well over 100 def F) including a full steam environment in the control cabinet (gotta plug those conduits) and it keeps on ticking). On the full steam problem, the DTC was dripping and stopped working - I dried it out and it worked fine."