andrews CWH 30/201, Operating Instructions Manual

Page: 37 / 48

Engineer 37 MAXXfl o EVO
4.5 COMPLETE PARAMETER LIST TABLE (CONTINUED)
PARAMETER DESCRIPTION FACTORY
DEFAULT
NOTES
DHW (continued)
1620 DHW release Time Programme
4
Defi nes when the heater is released for DHW heating
1630 DHW charging priority Absolute Only used when the controls are operating other space heat-
ing circuits
1640 Legionella function Off Used to activate function (operation modes are “Periodically”
or “Fixed weekday”
1641 Legionella function periodic 7 No of days before the legionella function will activate
1642 Legionella function day Sunday Fixed week day the legionella function will start
1644 Time for legionella function 01:00 Time the legionella function will start
1645 Legionella function setpoint 70
o
C The setpoint to be achieved for the legionella function (max
75
o
C). If B39 is installed and the function setpoint cannot be
achieved (because of pipe work heat losses) try lowering the
setpoint and increasing the dwell time. Note: The higher the
setpoint the shorter the required dwelling time.
1646 Dwelling time at legionella
function setpoint 10 mins The length of time the DHW tank sensors and B39 circula-
tion return sensor (if fi tted) are required to remain at setpoint.
If the legionella function cannot be performed successfully
within a 48 hour period, an error message will be displayed.
If no dwelling time is set, the legionella function is completed
the moment the setpoint is met.
1647 Legionella function circula-
tion pump Off When the function is activated, the circulating pump is
switched on while the “Legionella” function is performed as
soon as the tank temperature acquired by the sensor lies
above the “Legionella function setpoint” minus 1 K. The pump
runs during he dwelling time set. If the tank temperature falls
below the demanded “Legionella function setpoint” by more
than the DHW switching diff erential plus 2 K, the circulating
pump will prematurely be deactivated.
24h / day
When this setting is used, DHW heating is continu-
ously released as long as it is switched on.
Time program 4/DHW
When using this setting, a specifi c time program is
available for DHW heating. For every weekday, a
time program with a maximum of three on phases
can be set. During the release time, the nominal
DHW setpoint applies, outside the release time, the
reduced DHW setpoint. If the legionella function is
pending, it will be performed when DHW heating
is released for the fi rst time in the morning. Set-
ting “Once / several times per day” has no impact.
If DHW heating is switched off , the frost protection
setpoint will apply.
Periodically
The legionella function is repeated according to the
interval set (operating line 1641).
Fixed weekday
The legionella function can be activated on a fi xed
weekday (operating line 1642). When using this setting,
heating up to the legionella setpoint takes place on the
selected weekday, independent of previous storage tank
temperatures.