OJ Electronics WLM2-1BA, User Manual

10

-3ºC

Max allowed supply water temperature.

Winter

Outdoor temperature

Winter

Design supply water temperature at outdoor temperature –3°C

Design supply water temperature if used 

without

outdoor compensation module. 

Return

Summer

Outdoor temperature

Summer

Supply water temperature at outdoor temperature 25ºC

Return

Supply Water Temperature Control

Using supply water sensor for limitation of supply water:

A limit sensor should be used with the WLM 1FS & WLM 3FS, but can be used without the weather compensation module (WLOC). In this case the

master will control the supply water temperature flowing into the system via the 3 or 4 port mixing valve and actuator. The factory default setting is 45°C,

but can be changed via the master display. 

Using outdoor compensation module for weather compensation

When the outdoor compensation module (WLOC) is connected to the system, the master calculates the correct temperature, taking into account  the

heat losses that will vary depending on the outdoor temperature, and the room temperature requirements of the system. For example, on a day when the

outdoor temperature is 12°C, it is possible to run the heating system with a supply water temperature of only 35°C. this ensures economical running of

the boilers, and comfortable room conditions throughout the year. The max allowed supply water temperatur prevents excessive water temperatures if

the outdoor temperature becomes extremely cold, e.g. - 30°C.

45ºC

25ºC

30ºC

55ºC

Max supply temperture

The max allowed supply water temperature is set according to the design

requirements of the installation (line  A on the curve). This is the safely

maximum. 

Weather compensation

Winter

A design outdoor temperature and the corresponding design supply

water temperature are set (point B). To increase the heat output, adjust

the supply water temperature higher, until you feel comfortable (we

recommend only a 2 degree adjustment of this temperature at a time, and

timer allowed for the system to respond).

Summer

An outdoor temperature and the corresponding supply water temperature

are set (point C). To increase the heat output, adjust the supply water

temperature higher (we recommend only a 2 degree adjustment of this

temperature at a time, and timer allowed for the system to respond)

The master calculates the intersection point D

Compensation for outdoor temperature can only be done if an outdoor

compensation module (WLOC) is installed. Without outdoor

compensation module the Master will adjust after allowed supply water

temperature 45°C.

Line 1: Factory settings

Line 2: Example on modified settings

22

Max supply temperature

The max allowed supply water temperature is set according to the design requirements of the 

installation (line A on the curve). This is the safely maximum.

Weather compensation

Winter

A design outdoor temperature and the corresponding design supply

water temperature are set (point b). To increase the heat output, adjust

the supply water temperature higher, until you feel comfortable (we

recommend only a 2 degree adjustment of this temperature at a time, and

time allowed for the system to respond).

Summer

An outdoor temperature and the corresponding supply water temperature

are set (point C). Set the outdoor temperature at the level where heating will no longer be 

required (this is known as the summer shut down temperature) Default setting is 20˚C.

Then set the supply water temperature that you require when the outside temperature is at 

20˚C. The default is 25˚C.

To start the summer shut down at a lower temperature level, reduce the outdoor    

temperature setting, and/or reduce the supply water temperature at this setting.

The master calculates the supply water temperature on the line C to 1 if an outdoor design  

temperature of -3˚C is selected, or on the line C to 2 if the outdoor is selected at -10˚C. The  

intersection point on the line of the actual outdoor temperature indicates the calculated  

supply water temperature.

Compensation for outdoor temperature can only be done if an outdoor compensation  

module (WLOC) is installed. Without outdoor compensation module the Master will adjust  

the supply temperature after the design supply water temperature winter setpoint (default  

45°C).

Line 1: Factory settings

Line 2: Example on modified settings

Master with Display 

type W

lM2