HeatNet Smith Series, Руководство пользователя, Страница: 75 / 82

APPENDIX A HeatNet Control REV 1.38-1
Page 75
*Status Screen Fault Display
There are numerous interlock switches and software limits
that are detected. Each of these, when tripped will produce a
display message, an audible beeping, and an alarm relay
closure. The fault is displayed first, then after a second, the
time the fault occurred is displayed. This cycle will keep
occurring until the fault is cleared.
These faults and interlocks are:
HIGH LIMIT:
When the high limit aquastat trips the following message is
displayed:
The high limit interlock breaks power to the ignition control
(shutting it off) and effectively removes any chance of the
gas valve receiving power. The HeatNet series control will
remain powered to display the fault, latch the alarm
relay/audible beeper, and to access the log. The interlock is
located on J5, HIGH LIMIT. Ensure power is present on the
input to the High Limit Control.
SPARE 4:
This is a reserved interlock input that is user defined. The
interlock is located on J5B, SPARE 4.
LOW WATER CUTOFF:
If there is a low water condition reported by the low water
cutoff switch this fault is displayed. Check that there is
water flow and water in the boiler. There is a reset switch
located on the LWCO box. The interlock connection is
located on J5B, LWCO.
GAS PRESSURE:
The gas pressure switches (high pressure and low pressure)
are connected in series, so if either trip, a fault will be
reported here. A reset switch is located on the gas pressure
switches. The interlock is located on J15B, GAS PR.
SYSTEM WATER FLOW:
Once the HeatNet series boiler receives a call for heat, it
closes the system circulator pump relay. It then waits 10
seconds or more (adjustable) to prove flow. If there is no
flow, the flow switch alarm will be set. Every 10 seconds
the circulator pump relay will cycle ON for 10 seconds and
then OFF for 10 seconds to try and establish flow. The
interlock connection is located on J5B, SYSTEM WTR
FLOW.