Strebel S-CB Px 120, Руководство по установке, эксплуатации и техническому обслуживанию

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S-CB Px 120 Manual 97
Continuation of ´Flue temp high´ message:
Cause:
There is no water in the unit while firing.
Corrective action:
This is an unlikely situation while all the safeties for checking the water presence didn't
detect anything. Only a lot of air in the system/unit (under pressure) can cause the water
pressure switch to switch while no water is present. Also the water leak detection
did not react. Bleed all air from the unit so the heat from combustion can be transferred to
the water and won't leave through the flue system.
Cause:
Heat exchanger failure.
Corrective action:
This is an unlikely situation but when there is severe damage to the heat exchanger, the
combustion product will not be able to transfer all heat to the system water. The heat that
is not transferred will convert to an increased flue gas temperature.
Display message
A n t i c y c l e t i m e
9 9 9 , 5 h r s
Reason The controller received a new heat demand too fast after the last
ended demand.
Cause:
Immediately opening and closing of the external thermostat.
Corrective action:
Controlled water flow cools down too quickly after loss of heat demand.
Controlled water flow heats up too quickly after start of heat demand.
Immediately opening and closing of the external thermostat. Check switching differential
of the ON/OFF thermostat.
Controller settings need to be changed. Be aware that the standard settings work fine for
all common systems. When anti-cycling is active, because of immediate heating or cool-
ing of the controlled water flow/temperature, it concerns an unconventional system.
Display message
W a t e r p r e s s u r e f a u l t
9 9 9 , 5 h r s
Reason Water pressure is too low or high.
Cause:
The water pressure in the system is too high.
Corrective action:
Check if the system pressure is too high after (re)filling.
Make sure that there is a pressure relief valve and expansion vessel installed in the sys-
tem, according to the applicable standards.
Check if there is an open connection between the unit and the relief valve plus expansion
vessel.
Be aware that if the unit is installed in the basement of a tall building, only the static pres-
sure of the water column above the units can raise above the maximum allowable limits.
Make sure that this is not the case.
Cause:
The water pressure in the system is too low.
Corrective action:
Check if there is no leakage in the system that causes the pressure to drop. Fix any leak-
age and fill the system.
Check if there is an external system pump that sucks water through the boiler, causing an
underpressure. (bad installation design).