OJ Electronics WLM3 Installation Manual Download Page 19

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Type WLHX3

• A network must always contain a “network controlling master”.

• On masters set for the same string (same setting on the left encoder), all pumps, boiler and valve

outputs will act simultaneously, enabling the use of a common pump on each string.

• If only one UHF pump is used in a network, DIP-8 on the network controlling master must be set to

“ON”, enabling the UHF pump output on this master to control a common pump for the whole system.

• All masters in a network follow the same synchronized timing for actuators, pumps, boilers and mixing

valve output.

• If a lower supply water temperature is needed on one of the strings, the first master on this string

should be an FS master with a local mixing valve and supply water sensor attached.

• With FS masters, a special status menu is available on the network controlling master when a network

is detected. With this menu, it is possible to check the network. Please refer to the USER MANUAL for

further instructions.

NOTE: For instructions on testing a network, see “Power-up recommendations”.

using cooling functions

In addition to controlling heating, all WLM3 masters have the ability to control the cooling system.
• To enable the cooling function, a remote heating/cooling changeover module, WLAC3, and optional

humidity sensor, WLHX3, must be connected.

• Alternatively, the cooling switch input on the master can be used to switch between heating and cooling.
• For instructions on using the X-OUTPUT as a cooling signal to control a chiller, reversible heat pump or

diverting valve, see “Free relay function (X-OUTPUT)”.

• With BA masters, where dew point control is required, it is also necessary to install a sensor (ETF-522) on

the return water pipe of the floor heating system. The sensor must be connected to terminals 49 and 50.

using the WlaC3 module:

• The WLAC3 module must be installed in a convenient position for the user and connected to the sensor/

controller bus as shown in the drawing.

• If a BMS system in used for the heating/cooling decision, a volt-free BMS signal (EXT) can be connected

to the WLAC3 and the slider switch on the right side of the WLAC3 must be set to the heating position

(in this situation the BMS signal has priority and we recommend that the slider switch button be removed

to avoid unintentional override). Alternatively the volt-free BMS signal (EXT) can be connected directly to

terminals 47 and 48.

Humidity sensor WlHX3:

• With a WLHX3 humidity sensor, the system can limit condensation on floor surfaces due to high humidity.
• The WLHX3 must be installed in a room that is representative of the general humidity level in the building

and connected to the sensor/controller bus. More than one WLHX3 can be used if necessary, e.g. on

separate floors of the building. Where more than one humidity sensor is used, the master will use the

reading from the sensor detecting the highest dew point for control purposes.

pecial functions

BR1026A08a

WLAC 3

Sensor/

controller

bus

EXT.

-G

BR1026A08a