Weather-Rite XT112, Installation, Operation & Service Manual

Page: 58 / 98

S
ERIES
XT I
NSTALLATION
, O
PERATION AND
S
ERVICE
M
ANUAL
52
2. Air Flow - This indicator comes on at the same
time as the one abo v e. This is beca u se the
act u al circ u it is not u sed and is j u mped o u t. It
can be u sed as a tro u bleshooting g u ide, that
po w er is present to terminals #6 and #8 in the
flame safeg u ard.
3. PTFI - This acronym stands for Pilot Trial For
Ignition. This indicator is on only d u ring the trial
for ignition period. It indicates that terminal #3
(pilot
v al v e) and terminal #4 (ignition mod u le),
in the flame safeg u ard, ha v e been t u rned on.
4. Flame On - This indicator comes on after the
flame safeg u ard has pro v en o u t the flame sig-
nal. It also sho w s that the main v al v es ha v e
been acti v ated in the eq u ipment. On the safe-
g u ard control, terminal #5 is po w ered u p.
5. Alarm - This indicates that a safety locko u t has
occ u rred, w hether by loss of flame signal or
fail u re to ignite.
17.3.2.1 Fireye ® M4RT1 Flame Safe g uard Opera-
tion (ANSI, FM < 2.5MBH and XL < 1MBH)
The follo w ing w ill describe the internal operation of a
flame safeg u ard and the external f u nctions that w ill
take place. We w ill j u st trace the electromechanical
steps and not the electronic net w ork.
• All interlocks, control relays and safety limits are
closed. Po w er is s u pplied to terminal #7 of the
flame safeg u ard.
• The Operating Control LED ill u minates.
• The electronic net w ork is no w po w ered u p w hich
ill u minates the Air Flo w LED.
NOTE: The airflo w circ u it of the safeg u ard control is
not u sed and is j u mped. This is w hy the Air Flo w LED
ill u minates w ith the Operating Control LED.
• Follo w ing a short time delay period (p u rge cycle)
determined by the j u mpers, See Page 53, Figure
28 and Page 53, Table 13
. The electronic net w ork
closes a contact that po w ers u p terminal #3 and
terminal #4 in the safeg u ard control.
• Terminal #3 po w ers u p the eq u ipment's pilot gas
solenoid v al v e w hich opens allo w ing gas to flo w .
• Terminal #4 po w ers u p the ignition mod u le
creating the spark at the b u rner.
• This lasts for 10 seconds. This cycle is called trial
for ignition. D u ring this time period, the PTFI LED
is ill u minated.
• When the flame sensor detects a pilot flame, the
signal is sent back to the safeg u ard control. The
electronic net w ork ill u minates the FLAME LED.
• It closes a contact, w hich po w ers u p terminal #5
in the control. This terminal po w ers u p the main
gas v al v es allo w ing the main b u rner to come on.
• At the same time the electronic net w ork opens a
contact w hich remo v es po w er from terminal #4.
This sh u ts off the po w er to the ignition mod u le,
w hich stops the spark at the b u rner. The
safeg u ard control at this point monitors the flame.
NOTE: If a pilot flame is not detected d u ring the 10
second trial for ignition, the pilot gas solenoid v al v e
and the ignition mod u le are t u rned off. A safety
locko u t occ u rs w hich sh u ts do w n the electronic
net w ork. The only LED that w ill be ill u minated at this
time w ill be the OPERATING CONTROL. 30 seconds
after the locko u t occ u rs, the alarm circ u it is po w ered
u p, ill u minating the ALARM LED. Man u al reset is
no w req u ired. Wait 10 seconds before resetting the
control to allo w the locko u t s w itch to cool do w n.
NOTE: If the flame signal is lost w hile the b u rner is
on, the ignition mod u le w ill be t u rned back on. A 10-
second re-light trial for ignition is started. The PTFI
LED
w ill ill u minate d u ring this time.If a flame signal is
detected, the main gas v al v es w ill t u rn back on and
the ignition mod u le w ill t u rn off. If a flame is not
detected d u ring this re-light trial, the pilot gas
solenoid v al v e and ignition mod u le w ill sh u t off. A
safety locko u t occ u rs w hich sh u ts do w n the
electronic net w ork. The only LED that w ill be
ill u minated at this time w ill be the OPERATING
CONTROL. Thirty seconds after the alarm locko u t
happens the alarm circ u it is po w ered u p, ill u minating
the ALARM LED. Man u al reset is no w req u ired. Wait
10 seconds before resetting the control to allo w the
locko u t s w itch to cool do w n.
17.3.2.2 Fireye® M4RT1 Flame Safe g uard (FM ≥
2.5MBH and XL ≥ 1MBH)
If the eq u ipment is ordered w ith a FM compliant
Manifold eq u al or o v er 2.5M BTU or XL compliant
eq u al to or o v er 1M BTU, certain seq u ences m u st be
pro v ided in the flame safeg u ard control. There is a
specified time for pre-p u rge, trial for ignition, and non
recycle.
1. Timed pre-pur g e
This m u st be a separate p u rge from the rest of