YASKAWA E7LVD002 Technical Manual page 91

Safety Interlock Circuit
A Control terminal block position (TB1-1) is provided to connect the series circuit of Normally Closed (NC) safety
devices such as: freeze-up thermostats, smoke/fire sensors, high pressure limits, temperature limits or vibration detectors.
Anytime all the safety device contacts are closed, the Drive or Bypass will operate. When any one of these contacts open,
the Drive or Bypass will immediately stop operating. This input is momentary, when a safety device contact re-closes, the
Drive or Bypass will return to operation.
On power up the E7L will display a red "Safety Open" LED in the "System Status" area of the front control panel if a
normally closed "Safety Circuit" has not been installed between TB1-1 and TB1-9 on PCB A2. This condition will
prevent Drive or Bypass operation.
One of the following three items needs to be done prior to start-up:
1) Install a NC "Safety Circuit" between TB1-1 and TB1-9 on PCB A2.
2) Install a jumper between TB1-1 and TB1-9 on PCB A2. This method should be used if a "Safety Circuit" will be
added later in the installation.
3) De-activate these terminals by moving DIP switch S2-7 to the ON position (toward the enclosure door). This solution
is only suggested if a "Safety Circuit" will never be applied to the drive system.
Building Automation System Interlock Circuit
This is a Drive and Bypass enable input. A control terminal block position (TB1-3) is provided to connect Normally Open
(NO) enabling contacts such as: damper end switches or occupied cycle timers. An open contact will override the run com-
mand, preventing Drive or Bypass operation until these input contacts are closed. For example, this input could insure that the
system dampers achieve an operating position before the fan is started in order to protect the ductwork from over pressure.
When a Run command is received in HAND or AUTO mode, the E7L will display a red "Damper/BAS" LED in the
"System Status" area of the front control panel. This condition will prevent Drive or Bypass operation.
One of the following three items needs to be done prior to start-up:
1) Install a "BAS Interlock Circuit" between TB1-3 and TB1-9 on PCB A2.
2) Install a jumper between TB1-3 and TB1-9 on PCB A2. This method should be used if a "BAS Interlock Circuit" will
be added later in the installation.
3) De-activate these terminals by moving DIP switch S2-8 to the ON position (toward the enclosure door). This solution
is only suggested if a "Safety Circuit" will never be applied to the drive system.
Start Up and Operation 4 - 13