Weather-Rite TT Series, Инструкция по установке, эксплуатации и обслуживанию

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SECTION 20: S
EQUENCE OF
O
PERATION
95 of 198
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 b een 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
b een 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 b y loss of flame signal or
fail u re to ignite.
20.4.2.1 Fireye ® M4RT1 Flame Safe g uard Opera-
tion (ANSI, FM < 2.5MBH and XL < 1MBH)
The follo w ing w ill descri b e 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 b y the j u mpers, See Page 96, Figure
83 and Page 96, Table 38 . 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 bu 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 b ack 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 bu 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 bu 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 b e ill u minated at this
time w ill b e 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 b efore 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 bu rner is
on, the ignition mod u le w ill b e t u rned b ack 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 b ack 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 b e
ill u minated at this time w ill b e 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 b efore resetting the control to allo w the
locko u t s w itch to cool do w n.
20.4.2.2 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 b e
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 b e a separate p u rge from the rest of
the system. The trial for ignition m u st b e
delayed b y 7 seconds w hile the b lo w er in the
u nit is r u nning. This is to g u arantee that there
are no com bu sti b le gases or v apors present in
the air stream d u ring bu rner ignition and light
off.
2. Trial for i g nition
The length of time m u st b e fixed at 10 seconds.
This is to pre v ent the ignition mod u le from con-