17
The MEP230H programmer operates the same as the MEP230 with the exception of an additional 8
second pilot stabilization. After flame is detected during the trial for ignition period, the powering of
Terminal 5 is delayed for eight (8) seconds. Terminal 4 remains powered during the stabilization
period. This function is offered primarily for two-stage light oil burners, to assure a specific delay
between light off of the first and second stage, and to provide additional ignition timing to improve
flame stabilization.
The MEP290 programmer operates the same as the MEP230 with the exception that post purge is
selectable from 0 to 90 seconds.
MEP235
The MEP235 programmer operates the same as the MEP230 except flame failure during the firing
period causes lockout. Dipswitch #6 refers to Recycle/Non-Recycle on a loss of air flow (Terminal 6)
after flame is proven. The running interlock circuit (Terminal 6) must be proven closed within 10 sec-
onds after start of a cycle.
MEP236
The MEP236 programmer provides a 3 second main flame stabilization period by keeping Terminal
#4 (igniter) energized while the main fuel valve (Terminal #5) opens. The MEP236 is to be used on
an intermittent pilot only.
TIMING CHARTS
Terminal #5 is energized 3 seconds after flame is detected.
Selectable Recycle/Non-Recycle operation on loss of flame after Terminal 5 energized.
Recycle on loss of interlock (air flow) after flame proven.
Selectable air flow (interlock circuit) proven at start.
Selectable purge times are 7, 30, 60 and 90 seconds.
TYPE MEP230
PROGRAMMING SEQUENCE
L1/7
ON
PURGE
COMPLETE
FIRING
PERIOD
L1/7
OFF
SELECTABLE PTFI
5 OR10 SEC
SELECTABLE
PURGE
7, 30, 60, 90 Seconds
8
T
E
R
M
I
N
A
L
S
3
4
5
SELECTABLE
POST PURGE
INTERLOCK
AIR FLOW
PROVEN
