Control of MINIB convectors

General division of controls

1. dry interiors
Types EB-A – the possible use of transformers: TT100, TT240, TT300 EB-B (TT100, TT240, TT300) EB-C (TT100, TT240, TT300) TE

2. humid and wet interiors
Types EB-A – the possible use of transformers: TT100, TT240, TT300 A1 (TT240-E1, TT300-E1) E1 (TT240-E1, TT300-E1)

Capacity control of convectors for dry interiors

Types EB-A – the possible use of transformers: TT100, TT240, TT300 EB-B (TT100, TT240, TT300) EB-C (TT100, TT240, TT300) TE

Heat output of convectors is achieved by electronic speed control of the fans. If equipped with electromagnetic valves then the output can be reduced to zero by closing the valve to prevent water flow.

Capacity control of convectors in normal (dry) areas

Minib have used brushless 12V DC motors to power fans in dry areas since 2005. The avantages of low voltage DC fans compared to conventional AC is in their lower energy consumption, noise level and greater reliability.

The latest innovation in control uses microprocessor regulation of the DC motors and employs intelligent feedback. Features of the new control are:

Control EB-A

The basic connection of the control EB-A with a possibility of the continuous fan speed control. The set temperature is automatically maintained in the room when using the termostat. The electronic control block EB* is set on the continuous speed control.

• Stable heat output throughout lifetime – no reduction in output due to wear or fouling
• Optimised output via the control settings
• Very low noise generation
• Electronic disconnection of the motor in case of debris falling into the trench
• Simple installation with reduced wiring and a choice of manual or automatic control
• Electronic board sealed against the ingress of moisture

Fan speed of all convectors is controlled by the electronic board (EB) fitted inside each convector. The boards monitor control inputs and set the fan speed based upon their evaluation.

The electronic board is used for the following types of control:

Control EB-A – Simple on/off switching of the fans by a thermostat. Fan speed is set by a potentiometer which can be mounted next to the thermostat or within the convector.

Control EB-B

The basic connection of the control EB-B

Control EB-B – Fan speed is automatically set based upon the switching cycle of the thermostat and heat output is regulated based on the deviation of room temperature from set point temperature.

Control EB-C

Control EB-C – In automatic mode control is as EB-B but the maximum fan speed is set using the switch on the thermostat. In manual mode the fan speed is set by the position of the switch on the thermostat but there is no further speed modulation.

The type of control is variable; only a jumper is required to be placed on the electronic block when 0 to 10V control is used (EB-A).

If several convectors are used in a single room then the control device (thermostat or potentiometer) can be placed on any of the convectors and will control all the units. The 12V DC terminals on the EB can be used as the power supply for thermostats such as TH0482 which require this type of supply.

Wiring diagram for the control by the superset system

The basic connection of the control EB with a possibility to control the fan speed through the central system with the output 0 to 10V. Fans are stopped in the range of the control voltage 0 to 3V; the voltage between 3 to 10V controls the fan speed in the range minimum - maximum. The EB electronic control block is set on the continous speed control.

Wireless thermostats can be used on control types EB-A and EB-B. The thermostat transmitter can be sited in a representative space in the room and the receiver positioned near its power supply. The switching contacts of the receiver should be wired as a standard thermostat to the control terminals on one of the convectors.

A wireless thermostat can also be used with control EB-C but an adaptor ADA-EB must be used between the receiver and the convector terminals.

A new innovation involves the use of electromagnetic valves within the convectors. When the electronic control senses that the fans have been off for 30 minutes the valve is closed reducing the output to zero. As the thermostat calls for heating again the valve is re-opened.

There can also be a thermal switch within the convector which prevents the operation of the fans when the water temperature is low, preventing the convector from blowing cold air.

Note. The 12V DC is disconnected on the terminal block when the thermal switch opens. If this voltage is used as the supply to a thermostat then it is recommended that the thermal switch is not used.

Electrical power distribution is identical for all types of convectors. Between the power supply and the connectors and interconnection between convectors three core CYKY cable should be used with black, brown and grey colours. Black and brown distribute 12V AC from the transformer and the grey wire is used for interconnection of the EB control signal. Wire cross-section should be selected based on the length of the cable runs and current loadings. It is possible to use any suitably coloured cables between the thermostats the convector control terminals.

Connection of EB controls to a thermostat controlling other heating/cooling devices

Fan speed for all types of convectors is controlled by a 0 to 10V DC signal. In some cases it is not possible to connect the convector control directly to the output terminals of a thermostat. This is the case when the thermostat is powered by a 230V AC or 24 VAC sup- ply and also controls other devices i.e. boilers or valves. In such cases an ADA-EB adaptor must be used which converts the 24 or 230V to the 0 to 10V required by the controller. The small dimen- sions of the adaptor (48x42x22mm) allow it to be fitted in a stan- dard installation box under the thermostat.
An example of the use of the adaptor is shown with control EB-C. The fan speed can be controlled via the three position switch on the thermostat. The adaptor input (heat) is connected to the ther- mostat terminal whose voltage controls the boiler. Switching of the thermostat contacts will switch both the fans and the boiler.
Consult Minib for use of the adaptor in other applications.

Capacity control of convectors for humid and wet environments

A1 (TT240-E1, TT300-E1), E1 (TT240-E1, TT300-E1)

Minib use 12V AC motors for fan convectors positioned in humid and wet environments. The AC motors have proved themselves over many years in these difficult circumstances. There are two types of control available: A1 and E1.

Control A1 – A thermostat switches the power from the transformer TT240-E1 (TT300-E1). Motors are connected to the output ter- minals of the transformer and fan speed is selected from the various transformer tappings (7, 9 or 12V AC).

Control E1 – Electronic circuits in control box Reg. E1 automatically evaluate the switching cycles of the thermostat and regulate the fan speed (low, medium, high) according to the deviation of set point from space temperature.

Control A1

(wet interiors, On/Off)

Max. length of connected convectors is 12 linear meters.

Control A1 - the convectors can be connected in series if the distance from the transformer is small. The Y-connection is more suitable when the distance to the furthest convector exceeds 20m. Tapping can be made in the electrical conduit box EMK on the wall or through WAGO terminals directly under the convec- fan-coil tor cover. Wires of the convector side terminals can be crossed. Middle terminals can remain unconnected. If the middle teminals are linked, there can be only interconnected the middle terminals. When the cable with colours “black“, „black“, „brown“ is used, use the brown wire for interconnection of middle terminals of the convectors.

Control E1

(wet interiors, automatic step speed control, programmable thermostat)

The max. length of convectors is 6m (8m).

Control E1 - The convectors can be connected in series if the distance from the transformer is small. The Y-con- nection is more suitable when the distance to the furthest convector exceeds 20m. Tapping can be made in the electrical conduit box EMK on the wall or through WAGO terminals directly under the convector cover. The thermostat can be also placed in term of electrical safety in the wet area because it is powered from batteries with the total voltage 3V and power supply of motors uses the safe voltage 12V AC. But it is recommended to place the thermostat on the place, where air humidity does not condensate in order to prevent batteries from their corrosion.

Control TE

(On / Off control for electric direct heating convectors; the thermostat also switches on spiral heating wires)

Control TE - KP – auxiliary contactor Control coil – 240V/50Hz Contacts – 240V/50Hz/Imax ohmic load Current Imax is set by the total heat input of all switched units. The contactor can be also a three-phase type, and then the total length of convectors can be divided into three same sections and every section can be connected to one phase. The contactor coil can be powered from any phase.

Selection proderure for suitable controls:

• Select suitable control in terms of environment and comfort level
• Calculate total electrical power input from total number of convectors and their electrical inputs, calculate number of transformers required from the result
• If more than one transformer required contact Minib for correct selection of transformer for dry environments. For wet environments follow wiring diagram for connection with multiple transformers

Example of suitable control selection:

Task: Find a solution for the control of 4 convectors around a swimming pool as shown below. Convector type: Coil KO -2 pcs 2500mm long, 2 pcs 3000mm long

The process:

1. Select control type – two types of wet control are available A1 or E1; select E1 for greater comfort
2. Determine number of transformers required. Calculate electrical inputs from catalogue data: 2-off @106VA, 2-off @ 111VA = 434VA which is greater than the TT240 or TT300 can handle
3. As more than one transformer is required we need to use one transformer on two convectors and one transformer on the other two. Units 1 and 2 have a total requirement of 217VA and units 3 and 4 have a total requirement of 217VA. Select 2-off transformers TT240-E1.
4. Final step is to order the control units: Standard supply, with the units, 1-off control E1 with transformer (1-off thermostat TH0108, control panel Reg. E1, transformer TT240-E1, link cable). Extra order, 1-off transformer TT240-E1, 1-off control panel Reg. E1, 1-off link cable

Technical information

• Regulation
• Examples of convector connections
• Physical properties
• Other information and instruction manual