120Vac, 208-250Vac or 12/24Vac/dc, 50/60Hz  ( specify model )

2F to 22F ( 1C to 12C ) Other ranges upon request.
1F to 20F ( 1C to 11C ) Other ranges upon request.
-16F to +208F (-26C to +98C) standard or depending upon temp. probe ordered
(-50C to +250C temperature ranges AVAILABLE upon request )
+/- 1F (0.5C) Celsius or Fahrenheit (selectable)

For Heating: LOAD ON when Temperature Difference Lower than "MIN" diff.  preset
        LOAD OFF when Temperature Difference higher than "MAX" diff.  preset
For Cooling:  LOAD ON when Temperature Difference Higher than "MAX" diff.  preset
        LOAD OFF when Temperature Difference Lower than "MIN" diff.  preset
( Other operating modes upon request )

2 x 3 digits, 7 segment, Super Bright LED
RED ( 0.36"  LED display digits )
+ POWER ON and LOAD ON indication
Current Temperature on both probes and ON Diff. and OFF Diff.  indication

SPST relay, 30 Amp, 250Vac (or custom)
SPST relay, 30 Amp, 250Vac (or custom)
OPTIONAL, SPST relay, 10 Amp, 250Vac (or custom)
OPTIONAL, SPST relay, 10 Amp, 250Vac (or custom)
OPTIONAL, piezo, 85dB internal

2 PROBES up to 500 feet  ( 150m ) away from controller  ( any type wire )
Standard +208F (+98C ) high temp. limit ( other limits optional )
Automatic with error display and protection
APPLICATIONS:

SOLAR HEATING control
SOLAR COOLING control
VENTILATION control
HUMIDITY control
Air Conditioning
HEATERS and CHILLERS
Other media Temperature
Heat /Cool process control
Specifications:

Supply:

"MAX" Differential range:
"MIN" Differential range:
Temp. control range:

Temp. Accuracy/units:

Control mode:





Display:

Display Data:

Load output 1:
Load output 2:
Load output 3:
Load output 4:
Alarm buzzer:

Probe wiring:
High Temp. protection:
Error detection:
series   DSD-2RT  Digital  DIFFERENTIAL  THERMOSTAT
with 2 external temperature sensors.
Output load up to 60 Amp / 250Vac with 2, 3 or 4 relays on-board


with 2 ROTARY controls :

1.  POWER ON/OFF and "OFF" Differential Preset
2.  "ON" Differential Preset
DIMENSIONS:

Face:  Stainless Steel with Lexan decal.
Body: ( W x H x D )
5-3/8" x 2.75" x 2"
136mm x 70mm x 51mm
DESCRIPTION:
Electronic, digital differential temperature controller designed for Solar Heating, Cooling, A/C, Ventilation, Humidity Control etc...
The "ON" and "OFF" or "MIN" and "MAX" Temperature  Difference  can be preset by rotating the knobs on the face.
The thermostat will control the output high power relays ( 1, 2, 3 or 4 relays on board ) that can be wired to a heater, fan, pump, A/C or other load.
The output relays contacts are isolated for wiring to any low or high voltage loads..

The two digital displays show both probes temperature readings as well as the Differential presets.
Models available for 120Vac, 208-250Vac, 12V or 24V AC/DC, 50/60Hz.

Other Features:
The probes may be wired up to 500 ft. ( 150 meters ) away from the controller.
The differential presets may be adjusted at any time.
Models with High and/or Low temperature limit are available as permanent or adjustable.
The temperature probes can be wired up to 500 ft. ( 150m )  away from the controller with an ordinary 2-conductor cable
Quiet, switching of high power loads.


Celsius or Fahrenheit  temperature units selectable.
INSTALLATION in Box or Wall ( Panel  ):

Designed to fit in a 3-Gang
electrical box or in a panel.
Face plate will sit flush with the wall.
Model:   DSD-2RT-2D-2CH-2HP-120-56-FN16P208-IHL200F-DONP3P22F-DOFP1P20F-2NA7100KB4100BLK
Differential Thermostat with rotary controls and 2 external probes included.
Operating range: -16F to +208F (-26C to +98C ). IN High Temp. Limit = +200 F( +93C ).
"MAX" Diff. preset range = 3F-22 F (2C-12C ). "MIN" Diff. preset range = 1F-20 F ( 1C-11C ).
2 High Power relays (30 Amp/250V  max each).
 
Option "2CH" = One relay for Heat and the other for A/C.or Fan. Either one or both can be used.
SELECTION of standard Temperature Probes :
TYPICAL WIRING EXAMPLES  ( click on images for more )
KERA Technologies Inc.    Toll Free:  1-866-829-4253
NA7100KB4100BLK


NA7100KB4100CHR


NA7100KB4100RDT



NA7100KB4100SQT


NA7100KB4100DPD


NA7100KB4100SHD



PT1000TC38550MM




NA7100KB4100PIPTR
OPTIONAL Plastic or Metal (SS)
Sensor Probe Plate
(model PPP4 or PPS4 ).
OPTIONAL:
Sensor Probe Guard
model PG5 (black or grey ) .
COMPLETE NUMBERING SYSTEM FOR SD series CONTROLLERS :
( click below to download PDF document )
Toll Free:  1- 866- 829- 4253
For 2 AC / DC Motors, Pumps, Fans
or other loads up to 2 x 30 Amp max.
With contactor for Very High load Power
Simple wiring for loads
up to 30 Amp max.
Model:  DSD-2RT-1D-2SH-2HP-120-56-DON24F-IHL95F-H2F-FN16P208-2NA7100KB4100BLK
Application Examples
For Heating or Cooling, Attic / Roof Ventilation and Humidity Control:
For Heating, Ventilation and Humidity Control in Switchgear (with High temp Limit ):
Differential Thermostat with rotary controls and 2 external probes included.
Operating range: -16F to +208F (-26C to +98C ). IN High Temp. Cut-Off Limit = +95 F( +35C ).
"ON" Diff. preset range = 2F-24 F (1C-13C ). "OFF" Hysteresis  = 2 F ( 1C ).
2 High Power relays (30 Amp/250V  max each).

Option "2SH" = Both relays close below "MIN" diff. and open above "MAX" diff.
Differential Thermostat with rotary controls and 2 external probes included. 
Operating range: -16F to +208F (-26C to +98C ). High Temp. Limit = +208 F( +98C ).
Adjustable IN Low Temp. Cut-Off Limit  +60F to +80 F( +16C to +27C ). Optional adjustable High Limit instead.
"ON" Diff. preset range = 1-20 F (0.5-11C ). "OFF" Hysteresis  = 1 F( 0.5C ).
2 High Power relays (30 Amp/250V max  each).

Option "2SC" = Both relays close above "MAX" diff. and open below "MIN" diff.
Model:  DSD-2RT-1DL-2SC-2HP-120-56-DON20F-ILLP60P80-H1F-FN16P208-2NA7100KB4100BLK
For Cooling or Ventilation with adjustable Low (or High)  Limit :
For Solar Heating Control
with selectable Low Temp Limit, High Temp Limit,
Overheat Protection and Freeze Protection :
Model:  DSD-2RT-SOL-2HP-1MP-120-56-DONP2P22F-DOFP1P20F-OFRA-OLL-OHLR-FN16P208-2NA7100KB4100BLK
Differential Thermostat with rotary controls and 2 external probes included.
Operating range: -16F to +208F (-26C to +98C ). ( other values on request )
"ON" Diff. preset range = 2F-22 F (1C-12C ). "OFF" Diff. preset range = 1F-20 F (0.5C-11C ).
Selectable OUT Low Temp. Cut-Off Limit at  +68 F ( +20C ). ( other values on request )
Selectable OUT Freeze Protection Auto Circulation ON at +42 F ( +5.5C ) ( other values on request )
Selectable OUT High Temp. Protection at +190 F( +87C ). Activates 3-rd  relay. ( other values on request )
2 High Power relays (30 Amp/250V  max each),  SPST each for 1 or 2 Circulating Pumps.
1 Medium Power relay (10 Amp/250V max),  SPST. for OUT Overheat
Protection.
NOTE:   CUSTOM  MODIFICATIONS  AVAILABLE  FOR  ALL  MODELS
For Heating and Air Conditioning :
Model:  DSD-2RT-2DACH-2HP-120-56-DONN4P12F-DOFN4P12F-H1F-FN16P208-2NA7100KB4100BLK
Differential Thermostat with rotary controls and 2 external probes included.
Operating range: -16F to +208F (-26C to +98C ). High Temp. Limit = + 208 F( +98C ).
Cooling:  "ON" Diff. preset range =  -4F to +12 F (-2C to +6C ). Hysteresis = 1F.
Heating:  "ON" Diff. preset range =  -4F to +12 F (-2C to +6C ). Hysteresis = 1F.
2 High Power relays (30 Amp/250V max  each). One for Heat and One for A/C.
Either one or both can be used.
This controller may be used to make the temperature in one area follow another area with adjustable offset.
Thermowell model:  BTW-100-05-075NPT
Brass, Stem = 4" , Bore = 0.2", 3/4 NPT thread
Thermowell model:  BTW-25-05-075NPT
Brass, Stem = 1" , Bore = 0.2", 3/4 NPT thread
Thermowell model:  BTW-25-05-025NPT
Brass, Stem = 1" , Bore = 0.2", 1/4 NPT thread
Solar Heating,  Attic / Roof Ventilation,  Switchgear Humidity prevention
- Hight Temp. Limit
- Low Temp. Limit
- ON and OFF Differential Preset
- Freeze Protection
- Overheat Protection

- Alarm Buzzer
OPTIONS:
House Attic / Roof ventilation
Fan
Inside
Sensor
Outside
Sensor
Switchgear humidity control or ventilation
Inside
Sensor
Outside
Sensor
Heater or Fan
Thermowell model:
SSTW-114-066-050NPT
Stainless Steel
Stem = 1-5/8"
Bore = 0.26"
1/2 NPT thread
Stainless Steel
Stem = 4-1/2"
Bore = 0.26"
1/2 NPT thread
Thermowell model:
SSTW-41-066-050NPT
Thermowell model:
SSTW-64-066-050NPT
Stainless Steel
Stem = 2-1/2"
Bore = 0.26"
1/2 NPT thread
Thermowell model:
SSTW-114-066-075NPT
Stainless Steel
Stem = 4-1/2"
Bore = 0.26"
3/4 NPT thread
Heat Exchanger
Solar
Collector
Water
Tank
DSD
Controller
Pump
Pump
Drainback
Reservoir
Hot
Water
Out
Cold
Water
In
Glycol
Water
Coax
Cross
Adapter
Optional
Overheat
Valve
FOR MORE SOLAR HEATING EXAMPLES CLICK HERE
Simple split drainback system with external heat exchanger and one standard tank.
Split pressurized system with a storage tank with internal heat exchanger and a service tank with electric booster.
Simple split pressurized system with one tank with internal heat exchanger.
Split pressurized system with external heat exchanger and one tank with electric booster.
Split pressurized system with a storage tank with internal heat exchanger and a service tank with gas booster.
Hot
Water
Out
Hot
Water
Out
Hot
Water
Out
Hot
Water
Out
Cold
Water
In
Cold
Water
In
Cold
Water
In
Cold
Water
In
Compensation
Tank
Compensation
Tank
Compensation
Tank
Compensation
Tank
Solar
Collector
Solar
Collector
Solar
Collector
Solar
Collector
Optional
DSD
Controller
DSD
Controller
DSD
Controller
DSD
Controller
Heat Exchanger
Coax
Cross
Adapter
Water
Tank
Water
Tank
Storage
Tank
Electric Service
Tank
Storage
Tank
Gas Service
Tank
Optional
Overheat
Valve
Water
Water
Water
Glycol
Glycol
Glycol
Glycol
Electric
Booster
Gas
Booster
Optional
Overheat
Valve
Pump
Pump
Pump
Pump
Pump
OPTIONAL
WT-805
Tank
Controller
Electric
Booster
Optional
Overheat
Valve
P/T
Valves
P/T
Valve
P/T
Valve
P/T
Valve
P/T
Valves
P/T
Valve
P/T
Valve
P/T
Valve
P/T
Valve
Solar Panel Temp. Probe
Solar Panel Temp. Probe
Solar Panel Temp. Probe
Solar Panel Temp. Probe
Solar Panel Temp. Probe
Tank
Temp.
Probe
Tank
Temp.
Probe
Tank Temp.
Probe
Tank
Temp.
Probe
Tank
Temp.
Probe
For 2 AC / DC Motors, Pumps, Fans
or other loads up to 2 x 30 Amp max.
and 1 additional Relay ( up to 10 Amp )
for Overheat or Freeze protection
TEMPERATURE PROBE WIRING EXTENDABLE
UP TO 500 FEET ( 150m ).
CUSTOM TEMPERATURE RANGES PER REQUEST
E-mail:  info@keracontrols.com
E-mail:  info@keracontrols.com
OPTIONAL
WT-805
Tank
Controller
OPTIONAL
WT-805
Tank
Controller
=  Both relays close below "MIN" diff. and open above "MAX" diff. Most often used for Heating.  OUT cooler than IN.
=  Both relays close above "MAX" diff. and open below "MIN" diff. Most often used for A/C and cooling Fan. OUT cooler than IN.
=  One relay closes below "MIN" diff. and opens above "MAX" diff. and the other relay closes above "MAX" diff. and opens below "MIN" diff.
    OUT cooler than IN. This model may be used when it is not sure if cooling ( or ventilation ) or heating will be required, or in
    some more complex applications.
=  Similar to 2SH and 2SC except that only 1 relay is installed instead of 2. This is helpful when a lower supply power cons. is required.
=  Similar to above, except IN is cooler than OUT. Normaly the same can be achieved by swapping the probes locations, however
     then the IN - OUT labelling on the face will become reversed.

=  One differential adjustable only, called "ON" differential. The "OFF" differential is calculated automatically as the (ON diff.) + Hysteresis .
     The Hysteresis value is usually permanently set in the controller.
=  The Hysteresis value, usually permanently set in the controller that has one adjustable differential only, called "ON" differential.
    The "OFF" differential is calculated automatically as the (ON diff.) + Hysteresis . The  "xx" in degrees Fahrenheit ( or C for Celsius ).
=  One differential adjustable only ( with Hysteresis ) and adjustable Low Temperature Limit also installed.
=  One differential adjustable only ( with Hysteresis ) and adjustable High Temperature Limit also installed.
=  Two differentials "MAXimum" and "MINimum" are adjustable separately. The controller will make sure that the span
    between them is maintained correctly.

=  ABSOLUTE differential mode of operation. The load is controlled irregardless if one probe is warmer or cooler than the other.
=  Two differentials "ON HEAT" and "ON COOL" are adjustable separately, one for Heating and the other for Cooling.
    The two relays will control heating and cooling respectively.
    This model will cause one area temperature to follow the temperature changes in another area within adjustable offsets.
=  Solar Control Differential mode. Includes Freeze, Low and High temperature protections
    and has 2 adjustable differentials and 2 or 3 relays on-board.

=  ALL OFF, Low Limit on IN temperature set permanently to "xx" degrees Fahrenheit ( or C for Celsius ).
=  ALL OFF, Low Limit on IN temperature Adjustable from "xx" to "yy" degrees Fahrenheit ( or C for Celsius ).
=  ALL OFF, Low Limit on OUT temperature set permanently to "xx" degrees Fahrenheit ( or C for Celsius ).
=  ALL OFF, High Limit on BOTH temperatures set permanently to "xx" degrees Fahrenheit ( or C for Celsius ).

=  ALL OFF, High Limit on IN temperature set permanently to "xx" degrees Fahrenheit ( or C for Celsius ).
=  ALL OFF, High Limit on IN temperature Adjustable from "xx" to "yy" degrees Fahrenheit ( or C for Celsius ).
=  ALL OFF, High Limit on OUT temperature set permanently to "xx" degrees Fahrenheit ( or C for Celsius ).
=  ALL OFF, High Limit on BOTH temperatures set permanently to "xx" degrees Fahrenheit ( or C for Celsius )
=  High Limit on OUT temperature set permanently to "xx" degrees Fahrenheit ( or C for Celsius ) and driving a relay when limit detected.
=  High Limit on OUT temperature adjustable from "xx" to "yy" degrees Fahrenheit ( or C for Celsius ) and driving a relay when limit detected.
Option "2SH"
Option "2SC"
Option "2CH"

            
Options "1SH" and "1SC"
Options 2ISH, 2ISC,
   2ICH, 1ISH, 1ISC

Option "1D"   
                        
Option "HxxF"

Option "1DL"
Option "1DH"
Option "2D"


Option "ABS"
Option "2DACH"
                           
                           
Option "SOL"


Option "ILLxxF" 
Option "ILLPxxPyyF" 
Option "OLLxxF"
Option "BLLxxF" or "LLxxF" 

Option "IHLxxF" 
Option "IHLPxxPyyF"
Option "OHLxxF" 
Option "BHLxxF" or "HLxxF" 
Option "OHLRxxF" 
Option "OHLRPxxPyyF" 
NOTE:
Our DSD-2 Differential Thermostat model numbers are fully descriptive

You DO NOT HAVE TO know the complete model number to order.

Please call our customer service and we will assign a correct model number for your application.
A short description of your application will be very helpful.


For further reference, below are some additional options numbers used in the series DSD-2 thermostats numbering system:

NOTE1: In the description of differential thermostats the designation "IN" and "OUT" is only symbolic,  and it does not necessarily mean that the "IN"  probe has to be "Inside" and the other " Outside". The sensor probes can be swapped by placing them in opposite locations in order to satisfy the correct control operation. However, remember that the temperature of the probe that is connected to the "IN" terminals wil be indicated on the "IN" section of the display and the probe connected to the "OUT" terminals wil be indicated on the "OUT" section of the display, and the controller operation will behave accordingly. 
NOTE 2: In many cases the DSD-2 thermostats may be ordered with more than one option. For example, it is possible to order the model DSD-2RT-2D-2SH...