Honeywell DTC 100/4 TD User Manual

DTC 100/4 TD

1

Differential thermostat for regulation of two heating

circuits in combination of solar and classic heating

with temperature display and regulation of burner or

electric heating element

DTC 100/4 TD

User’s manual

Installation and maintenance instructions

ID-2106-13-DTC100-4TD-Honeywell-170039

DTC 100/4 TD

2

DEAR CUSTOMER

Congratulations !

You have bought a DTC 100/4TD differential thermostat, manufactured according to the
latest quality and safety standards. It is made according to the state of art and efficiently
utilises solar energy or alternative sources for domestic water heating.
It is designed in compliance with strict criteria and requirements of West European markets
and enables efficient use of solar energy which enables considerable savings of other
sources for domestic water heating.
Our products are available in the markets for several years and satisfy the needs of de­manding customers from hot Greece to north Germany.
We are convinced that the use of our product will satisfy your needs too and help you to
save your money.

Thanks for your confidence !

The set consist of:

1. Differential thermostat DTC 100/4TD

2. T1 collector sensor with silicone conductor

3. T2 hot water tank sensor with PVC conductor

4. T3 sensor for installation in boiler or to upstream conduit in front of mixing valve (PVC)

5. T4 hot water tank sensor with PVC conductor

6. Fixing screws with wall inserts (2 pcs)

7. Clip for T4 sensor fastening with fixing springs

8. Instructions for use

9. Warranty certificate

In case any of these are missing or damaged, demand your seller to supply you with a
replacement.

Read these instructions carefully, as this will allow you to benefit from all the possibilities
offered by this product.

WARNING !

All examples listed in the instructions are merely indicative. The manufacturer accepts no
responsibility for incorrect hydraulic connection of machine part of installation.
Machine and electric installations should comply with all safety regulations defined by
law and the rules.

We reserve the right to modify the instructions and the technical data of the product
without prior notice

DTC 100/4 TD

3

GENERAL

DTC 100/4TD is a microprocessor aided double differential thermostat, designed for
heating of domestic water from two heating sources (collectors, boilers, heat pumps,...),
using its logic of additional energy source switching on (boiler of central heating system).
The thermostat controls two pumps or two motors actuated ball valves (EMV 800...) and
one burner or electric heating element.

The thermostat enables regulation of four parameters, i.e.:

1. Regulation of maximum temperature in hot water tank from 10 to 90°C.

2. Regulation of difference for higher exchanger from 2 to 15K (after-heating circuit)

3. Regulation of difference for lower exchanger from 2 to 15K (collector circuit)

4. Setting two working regimes - C.n.b (normal) and C.d.t. (switching off the limitation of
boiler temperature for collector circuit).
With first two regulation options you define how much the value of the source temperature
(collector, boiler,...) should exceed the temperature of water around the exchanger in hot
water tank, that the regulator activates the pump or opens the valve.
The difference is set in relation to the volume of heat losses of the system which depend
on lenghts of pipelines from source to hot water tank and on pipeline insulation.
Built-in digital display enables prompt reading of the temperatures of individual sensors
and of all set values as well.

OPERATION:

DTC 100/4TD double differential thermostat measures the temperature of two heating
sources (collectors, boiler, ...) and of two spots in user (hot water tank). Heating effect is
provided, when heating unit (heating element in hot water tank) exceeds the temperature
of the user (water in hot water tank) for at least 3 - 5K. Consequently minimum adjustable
difference is 2K (factory set to 5K).
When the temperature of the source exceeds the temperature around the exchanger for
at least 5K, the thermostat opens the valve (EMV...) or activates the pump; it closes the
valve or stops the pump, when temperature difference is one degree lower than pre-set value.
The thermostat also switches off a pump if pre-set temperature is reached in hot water
tank (adjustable from 10 to 90°C).
If gas flow boiler, oil boiler or electric heating element (which is switched off during summer
seasons), is connected to after-heating circuit, the regulator can switch on the boiler by
means of the third output, if domestic water is to be additionally heated by means of after­heating circuit. In summer seasons a few days of cloudy weather can appear or use of
domestic water increases. In such cases domestic water is to be after-heated from additional
source (central heating system boiler or electric heating element). Classic differential
thermostat would require hot boiler throughout the year, which is not recommended from
ecological and economic point of view. DTC 100/4TD, with its third additional output, enables
activation of after-heating source. When after-heating of water is required, regulator first
switches on the burner of the boiler and when the condition of difference for after-heating
circuit is also assured (pre-set difference of boiler has higher temperature than hot water
tank), pump is switched on.

DTC 100/4 TD

4

When pump operates for primary heating circuit (collectors), operation of after-heating
circuit and burner of boiler or electric heating element is prevented. This assures maximum
energy savings during summer seasons and is also the main role of solar systems.
The set comprises four sensors (T1, T2, T3, T4). Two of them are mounted into individual
heating sources and two into upper half of individual exchangers in hot water tank. T1 and
T2 are designed for primary (main) heating circuit, which heats entire quantity of water
in hot water tank (lower exchanger), where T1 is a sensor of heating source (generally
collectors) and T2 is a sensor in lower part of hot water tank. T3 and T4 are designed
for additional, i.e. after-heating circuit which additionally heats water in hot water tank
(upper exchanger). T3 is a sensor of heating source (generally boiler) and T4 is a sensor
in upper part of hot water tank.

TEHNICAL DATA:

Supply voltage ....................................... 230V, 50Hz +/- 10%

Power consumption ............................... 4 VA

Pump relay rating .................................. 3A/230VAC cos 0.6

Type of thermostat ................................. P

Max. measured temperature ................. 180°C

Min. measured temperature .................. -20°C

Adjustable temperature range ............... 10 - 90°C

Temperature difference settings ............

2 - 15K

Hysteresis of difference ......................... 2°K

Hysteresis of the thermostat .................. 3°K

Nr. of sensors ........................................

4

Nr. of outputs ......................................... 3 (230 VAC)

INSTALLATION OF THERMOSTAT:

Install the thermostat on hot water tank casing or close to it. Do not mount it under pipe
fittings or valves due to possible water dripping on its housing.

EXTERNAL CONNECTIONS:

DTC 100/4 TD

5

VDR resistor

Thermo-shrinkable

tubes

ELECTRIC CONNECTION:

Grounding wires
should be connected
to special terminal
pins situated on right
side of terminal strips.

WARNING:

Boiler control should be performed behind the main switch for burner but in front of boiler
thermostat. Care must be taken that differential thermostat and boiler connection are
performed at the same phase otherwise inter-phase contact can occur.

SENSOR INSTALLATION IN COLLECTOR:

Install it as immersion sensor in
collecting pipe at the top of the
collectors in provided sleeve

For cables longer than 15m we
recommend over-voltage protection
with VDR resistor.

flow
direction

T piece 1/2”

pipe 1/2”

extension
conductor

sensor conductor

Connection

to terminal pins

BOILER

TERMINAL CONNECTION
1,2 T1 sensor – heating source sensor (collectors, boiler…)
3,4 T2 sensor – hot water tank sensor
5,6 T3 sensor – heating source sensor for higher heating circuit (boiler)
7,8 T4 sensor – hot water tank sensor in upper part of hot water tank

neutral conductor
9 neutral conductor
10 phase for boiler (burner) switching on
11

neutral conductor
12 phase of pump for secondary heating circuit
13 neutral conductor
14 phase of pump for collector heating circuit
15 phase connector for mains 230V, 50 Hz
16 neutral conductor - connector for mains 230 V, 50 Hz