Yaskawa Z1000U HVAC Matrix Bypass - Manual (Page 438)

n Cable Loss Configuration and Behavior
This section describes the configurable cable loss feature of the drive. This feature offers a user maximum flexibility in
determining drive response to a loss of communication.
Drive Behavior at Loss of Communication
The drive can be configured to respond to an interval without receipt of a message in one of the following methods:
• Continue at last speed
• Continue at last speed with alarm
• Continue at preset speed
• Ramp to Stop with FB14 fault
• Coast to Stop with FB14 fault
• Emergency Stop with FB14 fault
Metasys N2 I/O
Three Metasys N2 outputs are used to select the desired behavior:
• AO 21 – Cable Loss Timeout
• AO 22 – Cable Loss Speed
• BO 11 – Communication Fault Enable
Table F.2 Cable Loss Behavior Summary
Behavior F6-03 Z3-05
Cable Loss Timeout
(AO 21)
Cable Loss Speed
(AO 22)
Communication Fault
Enable
(BO 11)
Decelerate to stop (stop time in C1-02) FB14
Fault.
Note: In Bypass mode, bypass
contactor will open and motor
will coast to stop.
0 3 Timeout Interval X On
Coast to stop FB14 fault.
Note: In Bypass mode, bypass
contactor will open and motor
will coast to stop.
1 3 Timeout Interval X On
Fast stop (stop time in C1-09) FB14 fault.
Note: In Bypass mode, bypass
contactor will open and motor
will coast to stop.
2 3 Timeout Interval X On
Continue at last speed 3 0 0 X X
Continue at last speed with alarm 3 1 Timeout Interval X On
Continue at preset speed with alarm 3 4 Timeout Interval Preset speed On
Note: 1. Communication must first be established and then lost for these features to function as described. If a bypass is powered-up without a
cable connected or with the master controller offline, a communications timeout does not occur.
2. For modes that describe the bypass running after a communications timeout, a run command must have been issued (BO 1 = ‘On’ or
BO 2 = ‘On’) prior to loss of communications. For safety purposes, the drive will not automatically restart from a stopped condition. If
a user requires the drive to restart automatically, additional external wiring is required to accomplish this (consult factory).
3. Upon expiration of the communications timeout interval, the FAULT LED lights and remains lit until communication is restored.
Continue at Last Speed
In this mode, Cable Loss Timeout (AO 21) is set to 0, disabling the cable loss feature. The other two settings Cable Loss Speed
(AO 22) and Communication Fault Enable (BO 11) are ignored. If communication is lost, the drive simply maintains its last
commanded state. The drive will not display an alarm or fault to indicate it has lost communication. This behavior can also
be achieved by setting parameter Z3–05 to “0”.
F.4 Bypass Operations by N2
438 YASKAWA SIEP YAIZ1D 01A Z1000U HVAC MATRIX Drive Bypass Technical Manual