Midco EC200 & EC300 - Manual (Page 9)

Midco International Inc.
9
8471 38
XI - Nozzle and Electrodes
When the EC 200 burner is to
be used at 150 MBH/hr and
below, or EC 300 burner is to
be used at 200 MBH/hr and
below, the air restrictors should
be installed on the burner head
to get the best combustion
performance.
For easy installation follow the
steps below.
1. Check the associated
package containing two
air restrictors (A & B), four
8-32 x 5/16 socket screws
and four #8-32 nuts.
NOTE: There is a slight difference between the two air restrictors.
2. Disassemble the blast tube from the blower housing by removing the nuts on the fl ange.
3. Put the air restrictor A in the place, see Figure 7 for reference. The air restrictor A should be
installed on the back side of the burner head; on the same side of the electrodes. Install one
screw in the middle hole of air restrictor and put one nut on the screw.
4. Put the air restrictor B in the place, see Figure 7 for reference. Install one screw in the middle
hole of air restrictor and put one nut on the screw.
5. Line up two air restrictors and put the other two screws in place. Then tighten four of them.
6. Assemble the blast tube back to the blower housing.
___________________________
DANGER: Be sure that the Main Manual Shut-Off Valve, Combination Valve and
Burner Power Switch are turned off before removing any parts for service.
- Service will normally consist of inspection and cleaning. Check the electrodes for deterioration
and the insulators for cracks. The electrodes are adjustable. If defective replace. Be sure to replace
the rubber boot over the spark electrode and treat electrode leads with care. Due to high voltage
any damage to the insulation is a potential leak path. When a new electrode is installed, be sure to
set the spark gap and fl ame sensor dimensions, as shown in Figure 8.
___________________________
Part 1 Installation
X - Air Restrictor
AIR RESTRICTOR 'A'
(5236-36)
EC 200/300
BURNER
HEAD
(5236-19)
(5236-20)
8-32 x 5/16"
SOCKET
SREW
EC 200/300
AIR RESTRICTOR 'B'
(5236-37)
#8-32 WASHER
Figure 7: Air Restrictors
5/32"
EC 300
5/32"
6 3 /4" +0
-1/4
5/8"
EC 200
5/8"
6 3/4" +0
-1/4
Side view drawings rotated to show demensions
Figure 8: Retention Plates
1.109"
1.061"
EC 300
1.061"
1.109"
1.164"
.631"
EC 200
1.164"
.631"
.17"
.08"