Weil-McLain Evergreen EVG 220 Manual page 55

®
gas
Field wiring
E. System supply and return temperature sensors –
Terminal Block P14 (EVG control module, left side)
1. Two strap-on temperature sensors are shipped with the boiler. Attach one
to the system supply piping and the other to the system return piping. For
piping larger than 5 inch diameter or nonmetallic piping, using immersion
sensors will provide faster response.
2. Locate the supply sensor at least six pipe diameters, but no further than 3
feet, downstream from the boiler connection to the main to ensure adequate
mixing.
3. Supply sensor – wire between P14 #1 and #2 (common).
4. Return sensor – wire between P14 #3 and #2 (common).
5. Thermostat wire can be used to connect these sensors.
6. The Control compares the system return temperature with the system supply
temperature. Should the return temperature ever exceed the supply tempera-
ture, the Control knows there is likely a sensor failure and will report this
problem on the display.
All heating systems shown in this manual require the System Sup-
ply and Return sensors to be installed for proper control function.
System will not properly provide heat if sensors are not installed
according to these instructions.
F. Outdoor temperature sensor –
Terminal Block P10 (EVG control module, left side)
1. The control provides programmable options if using an outdoor tempera-
ture sensor. This sensor is supplied with the boiler.
2. The outdoor sensor must be installed unless specifically ex-
empted in the Energy Act statement on page 129.
3. Mount the outdoor sensor on an exterior wall, shielded from direct sunlight
or flow of heat or cooling from other sources.
4. The wire outlet on the sensor must be oriented DOWN to prevent water
entry.
5. Connect the sensor leads to the terminal shown at right and in the wiring
diagrams (see Figure 65, page 59). Thermostat wire can be used to connect
the sensor.
G. External limits –
To cause MANUAL reset: Terminal Block P13 #1 & #2 (EVG control module, left side)
EVG control will require manual reset after circuit is interrupted.
1. Remove factory-installed jumper and connect isolated contacts of external
limits across P13 pins 1 and 2 to cause the control to enter manual reset
lockout if the limit circuit opens. The limit must close and the control must
be manually reset using the procedure given in this manual. See drawing
at right and wiring diagram (Figure 65, page 59).
The control will lockout when a limit in its manual reset circuit
opens (P13 pins 1 & 2). The control activates its alarm terminals
and shuts the boiler down. An operator (user or technician) must
manually reset the control to restart the boiler.
Part number 550-100-131/0120
-
fired water boiler
(see wiring diagram, Figure 65, page 59)(continued)
REQUIRED unless exempted
OPTIONAL
— 220/299/300/399 Boiler Manual
REQUIRED
Strap to supply & return piping
See Figure 65, page 59 for details.
See Figure 65, page 59 for details.
See Figure 65, page 59 for details.
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