Siemens LMV 5 Series, Technical Instructions, Page: 343 / 374

LMV Series Technical Instructions
Document No. LV5-8000
SCC Inc. Page 13 Appendix A
Hot Standby with a Temperature Switch (continued)
Procedure
1. Set the LMV5 for load control operating mode “ExtLC X5-03” through the following
menu path:
Params & Display > LoadController > Configuration > LC_OptgMode =
ExtLC X5-03
2. Wire a jumper between terminals X5-03.4 and X5-03.2 on the LMV5. Terminal X5-03.4
outputs 120 Vac at all times. When the LMV5 is in operating mode “ExtLC X5-03” and
120 Vac is on terminal X5-03.2, the LMV5’s firing rate decreases.
3. Wire the temperature switch contact between terminals X62.1 and X62.2 on the LMV5.
This needs to be a normally-open contact that closes once the temperature of the boiler
rises above the temperature setting on the temperature switch.
Operation
1. When the temperature of the boiler is below the temperature switch setting, the
contact between X62.1 and X62.2 will be open. The LMV5 will be in operating mode
“ExtLC X5-03”, waiting for a 3-position input for its firing rate command. Since line
power from terminal X5-03.4 has been directly connected to the terminal that
decreases the firing rate (X5-03.2), the LMV5 will remain at low fire.
2. Once the temperature rises above the temperature switch setting, the contact between
X62.1 and X62.2 closes. The LMV5 changes to operating mode “IntLC” and modulates to
maintain setpoint W1.
X5-03.4 X5-03.2
Temperature switch contact
X62.2
X62.1
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