andrews CWH 30/201, Operating Instructions Manual

Page: 34 / 48

Engineer 34 MAXXfl o EVO
Phase
No:
Phase
display
reference
code
Phase Phase description Explanation
1 TNB Homerun Permitted afterburn
time Not relevant for the MAXXfl o EVO
2 TLO Homerun Permitted time with air
pressure switch closed
or fan speed Time after post purge when the air fl ap is still open as the fan
speed runs down
3 TNN Homerun Permitted time with fan
speed Time after post purge when the fan is permitted to run on
4 STY Standby No demand No heat demand, burner is not active
5 STV Standby Start prevention Burner held until a temporary condition has been removed (e.g.
B2 sensor disconnected)
6 THL1 Startup Fan ramp-up time to
ignition speed Maximum fan ramp-up time for fan to reach pre-purge speed
7 THL1A Startup Fan ramp-up time to
ignition speed Maximum fan ramp-up time for fan to reach ignition speed
8 TV Startup Pre-purging Fan pre-purging phase
9 TBRE Startup Fan adjustment Maximum time required to reach ignition level after pre-purging
10 TW1 Startup Waiting time Maximum waiting time until the following functions complete:
- Internal safety tests
- Fan speed adjustment to ignition load
11 TW2 Startup Waiting time Fan speed adjustment to ignition load
12 TVZ Startup Pre-ignition phase Time before ignition (minimum 0.2 seconds)
13 TSA1 Safety time 1st safety time First part of safety time with spark on and gas valve open
14 TSA2 Safety time 2nd safety time Second part of safety time with spark off and gas valve open
15 TI Operation Interval Stabilisation of fl ame (5 seconds)
16 MOD Operation Control mode Burner is modulating normally - Main phase of operation
17 THL2 Shutdown Post purging Post purging at last operating fan speed - Demand has been
turned off , gas valve will be closed
18 THL2A Shutdown Post purging Post purging at pre-purge fan speed - Demand has been turned
off , gas valve will be closed.
19 TN1 Shutdown Post purging Post purging at last operating fan speed - Demand has been
turned off , gas valve will be closed
20 SAF Error Boiler error state Certain types of error can force the heater control to jump to this
phase and all safety related outputs are deactivated. When the
condition returns to normal, this phase will be skipped and the
control will restart. This will avoid lockout and the need to reset.
21 STOE Error Boiler error state If the heater controls detect a system error that would drive the
heater into an unsafe state (i.e. lockout), the heater controls will
jump to this phase. Only an applied reset can resume operation.
22 TNA Shutdown Post purging at pre-
purge speed Last phase of fan post purge before the boiler controls go to
standby phase.
23 KT Standby Start prevention Temporary start prevention condition becomes a permanent con-
dition after a period of time has elapsed.
24 TN2 Shutdown Interruptable post
purging Interruptable post purging at last fan operation speed. If there is a
new heat demand during the post purge period, post purging can
immediately be interrupted.
4.3 ERROR HISTORY - BURNER CONTROL PHASE