Weil-McLain Evergreen EVG 70 Manual page 58

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Field wiring
E. System supply and return temperature sensors –
Terminal Block P14 (EVG control module)
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
temperature, the Control knows there is likely a sensor failure and will report
this problem on the display.
All primary/secondary heating systems shown in this manual require
the System Supply 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)
1. The control provides programmable options if using an outdoor
temperature sensor. This sensor is supplied with the boiler.
2. The outdoor sensor must be installed unless specifically
exempted in the Energy Act statement on page 139 .
3. Mount the outdoor sensor on an exterior wall, shielded from direct sunlight
or fl ow 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 60, page 62 ). Thermostat wire can be used to connect
the sensor.
G. External limits –
To cause MANUAL reset: Terminal Block P13 #1 & #2 (EVG control module)
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 60, page 62 .
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.
58
as-fired water boiler —
(see wiring diagram, Figure 60, page 62 ) (continued)
OPTIONAL
70/110/155
REQUIRED unless exempted
Boiler Manual
REQUIRED
Strap to supply & return piping
See Figure 60, page 62 for details.
See Figure 60, page 62 for details.
See Figure 60, page 62 for details.
Part number 550-100-191/0917