4
a “first out” basis. The first switch which opens in the string to cause the condition will be displayed.
The 3-P circuit is immediately monitored after a burner start-up.
When a “lockout” condition is manually reset, the display on the BurnerLogix and the Interlock
Annunciator Module is ready to begin a new burner sequence. Note the section
Lockouts
in the Bul-
letin BL-1001 or BLZ-1001.
Whenever more than one interlock switch in the L1-3 circuit is open on a start-up, the open interlock
switch wired in the sequence closest to the L1 terminal will be displayed. Whenever more than one
interlock switch in the 3-P circuit is open on a startup, the open interlock switch closest to terminal 3
will be displayed.
The YZ300 (YZ320) must be connected to the BurnerLogix control to provide access to the addi-
tional lockout messages associated with the YZ300 (YZ320) Expansion Module.
In operation, the 3 to P and L1 to 3 circuits are checked each half cycle by separate photo optical
couplers in the BurnerLogix system to determine if any interlock is open. Upon detecting an open
interlock, the BurnerLogix control initiates a LOCKOUT or HOLD message, then requests informa-
tion from the YZ300 (YZ320) to determine which interlock corresponding to terminals 43 through
59 and L1 through 42 (on YZ300 [YZ320]) to determine which of the interlocks closest to terminal 3
(3-P circuit) or closest to terminal L1 (L1-3 circuit) is open. The BurnerLogix then selects the corre-
sponding message from the stored message list and displays it. The YZ300 (YZ320) messages then
become a part of the historical data which is stored in the BurnerLogix system memory.
Any interlock in the 3-P or in the L1-3 circuit that opens for at least 33-50 ms while the burner is ON,
or for at least 66 ms while the unit is in PURGE will cause the YZ300 (YZ320) and the BurnerLogix
control to respond with the proper message. Interlock contacts that temporarily open for shorter time
periods will be ignored. Refer to Figure 2 on page 8 for DEFAULT MESSAGES.
SPECIAL NOTES ON OPERATION
After the start of PTFI, if any recycle (L1-3) or running interlock (3-P) limit opens, the BurnerLogix
control will display a POST PURGE message for 15 (or selected post purge time) seconds before
displaying the appropriate message. The appropriate LED located on the face of the YZ300 (YZ320)
will flash to indicate in what section of the circuit the interlock is open.
On recycle type programmers (e.g. YP200 or YP300 set for recycle operation), if a running interlock
(3-P) limit opens, the control will shutdown, perform a post purge and then try to restart. The control
will hold for ten (10) minutes during purge waiting for the limit to close. If a second running inter-
lock opens during this "hold" period, the message may change to reflect the new interlock.
If the operating control limit or auxiliary limit #1, #2 or #3 opens during a firing cycle, the control
will initiate a 15 second post purge and then go to standby and display the message pertaining to the
interlock that opened. The BurnerLogix will wait for all interlocks in the L1-3 circuit to close to
begin a new cycle.
If multiple interlocks in the 3-P circuit are opened during the start of a burner cycle, the first inter-
lock in the following sequence will be displayed.
CAUTION: The YZ300 (YZ320) messages are stored within the Interlock Annunciator
Module. The YZ300 (YZ320) messages shown in Table 2 on page 5, and on the wiring dia-
gram, Figure 2 on page 8, represent the default messages that are shipped with each Inter-
lock Annunciator module. Unless these default messages are modified via the BLL510 or
BLV512 display module or customized via a PC (Refer to CUSTOMIZING YZ300
(YZ320) MESSAGES in this bulletin), the YZ300 (YZ320) must be wired EXACTLY AS
SHOWN, in the sequence as shown in the wiring diagram, Figure 2 on page 8, to ensure
proper operation.
