Difference Setpoint Control - Variable Speed Zoom

Difference Setpoint Control - Variable Speed


Brand: Tekmar

Qty Price
$244.85 $229.95
/ each
In Stock! Ships in 24-48 Hours
(5 Available)



Type: Variable Speed
Application: Alternative Energy
Width: 2-7/8"
Height: 4-3/4"
Difference Setpoint
User Interface: Push Button
Depth (Inches): 7/8"
Ambient Conditions: Indoor Only: -20°-120°F < 90% RH non-condensing
Power Supply: 24V
Min Temp (F): -30°F
Temperature Range (F): -30°-300°F
Max Temp (F): 300°F
Control: Microprocessor Control
Sensors: NTC Thermistor
10 k ohm @ 77°F
Enclosure Type: C
Weight (lbs): 1.5 lbs
Demands: 24 V (ac) 2 VA

Description for Tekmar 157

Control Description The Difference Setpoint Control 157 is designed to operate a variable speed pump to transfer heat from a heat source to a storage tank. Varying the speed of the pump provides fast and accurate temperature control to maintain the target temperature difference (ΔT). Additional minimum and maximum setpoints turn off the pump when heat transfer is no longer desirable. Potential applications include using solar collectors or a wood boiler as a heat source.



Microprocessor control; This is not a safety (limit) control

Packaged Weight

1.5 lb. (670 g)

Enclosure C, White PVC plastic


4-3/4" H x 2-7/8" W x 7/8" D (120 x 74 x 22 mm)


CSA certified to CSA C22.2 #142-M and UL # 508

Ambient Conditions

Indoor use only, -20 to 120°F (-30 to 50°C), < 90% RH non-condensing

Power Supply

24 V ±10% 50/60 Hz 3 VA

Variable Pump

120 V (ac) 2.4 A 1/6 hp, fuse T2.5 A 250 V

Pump 2

120 V (ac) 5 A 1/3 hp, pilot duty 240 VA


24 V (ac) 2 VA

Sensors Included

NTC thermistor, 10 kΩ @ 77°F (25°C ±0.2°C) ß=3892 Two of Universal Sensor 071

Difference Setpoint Control - Variable Speed


by PowerReviews
TekmarDifference Setpoint Control - Variable Speed

(based on 1 review)

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Excellent Product

By todd

from FL

Verified Buyer

Comments about Difference Setpoint Control - Variable Speed:

It is an excellent differential control for solar applications. It is very flexible for most common solar configurations. Currently I have mine setup with a drain back tank. What was most impressive is the intelligence of the unit and its ability to run standard TACO 007 pumps at variable speeds. It takes all of the guess work out of managing the flow rate to get the highest BTU out of the solar panel.

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