Xylem EPR IM Electric heater-circulator unit EPR (obsolete) - Manual (Page 12)

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Instruction manual Laing Electric heater circulator unit
www.lainginc.com
Functions
Main switch
The Electric heater circulator unit contains a main switch H which powers the
eloctronic control and thereby also controls on – off operation of the heating
elements. The main switch does not separate the unit from the main power
supply. This separation must be provided on site, taking in consideration all
applicable safety codes.
Fuses
To protect the electronic components, the control contains two fuses. The 35mA
fuse protects the processor control, the 1A fuse protects the circulator.
Constant temperature control
The constant temperature control function maintains the feed temperature
of the Electric heater circulator unit at a pre-set level. This is achieved by
measuring the outlet temperature and activating the three heating elements
in accordance with the selected program (See “Program selection for the
switching sequence of the heating elements ”).
The integrated constant temperature function is always activated. There-
fore, whenever an external control is used, the constant temperature has to be
set at or above the maximum temperature required by the external control.
The constant temperature can be set with the control knob K at the outside
of the housing. The range is from 86°F to 185°F.
When the electronic safety temperature limiter function is activated, the
selected constant temperature should always be at least 10K lower than
the safety temperature. Otherwise, under unfavorable conditions, the safety
temperature limiter function could be activated, which would shut down the
unit.
Overheating Protection
When the Electric heater circulator unit is used in connection with floor heating
it is strongly recommended to activate the integrated overheating protection
in order to avoid overheating damages due to failure of the control.
To activate this function, jumper 8 needs to be closed. The safety tempe-
rature should be set to the highest permissible temperature for the floor in a
range between 03°F and 194°F at the potentiometer S. This temperature
must be higher than the maximum temperature reached by the floor heating
system under normal conditions!
If activated, the control monitors the feed line temperature with an additional