SAS ST-550 zPID, User Manual

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ST-550 zPID
33
VIII.1.
Temperature alarm
This protection is activated only in operation mode (when the CH boiler temperature is lower than the
pre-set temperature value). If the CH boiler temperature does not increase within the period of time
defined by the user, an alarm is activated: feeder and fan are switched off and a sound signal is
activated. The display shows the following message:
‘Temperature not rising'.
Press the pulser knob to deactivate the alarm. The controller will resume the previously selected
operation mode.
VIII.2.
Thermal protection of CH boiler (STB)
ST-550 zPID controller is equipped with STB safety thermostat which protects the CH boiler against an
excessive temperature increase. When the temperature reaches 95⁰C (default setting: STB 95
o C), the
contacts in the fan and feeder power supply circuit are opened. They may be activated again only
manually by pressing ‘
reset ’ button on the safety thermostat casing after the CH boiler water cools down
and reaches the temperature of about 80⁰C.
VIII.3.
Automatic sensor control
If one of the temperature sensors (CH, DHW, screw feeder or fuel tank) is damaged, an alarm
sound is activated and the display message informs about the failure; e.g.: ' CH sensor damaged '. Both
the feeder and the fan are disabled. The pump operates regardless of current temperature.
If the CH sensor or feeder sensor is damaged, the alarm is active until a new sensor is installed. In the
case of DHW sensor damage, the alarm should be switched off by pressing
pulser knob – the controller
will restore operation with one pump (CH). A new sensor should be installed so that all modes of CH
boiler operation could be available.
VIII.4.
Protection against boiling of water in the CH boiler
This protection applies only to water boiler priority mode, in the case when the water tank is not
sufficiently heated. When the pre-set temperature of water tank is 55 O C whereas the actual CH boiler
temperature reaches 62 O C (so called priority temperature ), the controller disables the fan and the feeder.
If the CH boiler temperature still increases reaching 80 O C, the CH pump will be switched on. In the case
of further temperature increase, an alarm will be activated at the temperature of 85 O C. Such a situation
usually occurs when the water boiler or the pump is damaged or when the sensor is incorrectly mounted.
When the temperature drops, at 60
O C the controller enables the fan and feeder and it remains in
operation mode until the temperature of 62 O C is reached.
VIII.5.
Temperature protection
The regulator has an additional protection against hazardous temperature growth. If the alarm
temperature of 80
O C is exceeded, the fan is disabled and the pumps are switched on in order to distribute
hot water throughout the house installation. When the temperature of 85 O C is exceeded, an alarm is
activated and the display shows the following alarm message: ‘ Temperature too high’ . When the
temperature drops to a safe level, press pulser knob to deactivate the alarm. The controller will resume
the previous operation mode.
VIII.6.
Fuel feeder protection
There is an additional sensor measuring temperature on the screw feeder. In the event of a significant
temperature increase (above 80
O C), an alarm is activated: the feeder is for 10 minutes, which moves
the fuel into the combustion chamber. Feeder sensor prevents the fuel in the tank from igniting.
VIII.7.
Limt switch in the fuel tank
In the case of using ST-550zPID controller with such CH boilers as w SOLID, EFEKT, BIO SOLID, BIO
EFEKT, the controller monitors the fuel tank flap. Once it is opened, the controller automatically disables
the feeder and the fan.
VIII.8.
Fuse
The regulator has two WT 6.3A tube fuse-links protecting the network.
NOTE:
Higher amperage fuse should not be used as it may damage the controller