Table of Contents
Advertisement
Figure 6-1 - Example of Zone Temperature Control Setup
6.5. Alarm Conditions (Safety
Modes)
When certain conditions are detected, the
CUB-II and CUB-TD operate in a special mode
(called Safety mode) in order to correct the con-
dition or to prevent equipment, product, and/or
energy loss. Safety mode alarm conditions can
be reset two different ways:
1. Resetting the alarm in the E2 or Ein-
stein Alarm Log will reset all active
Safety mode alarms.
2. Defining an alarm reset input on the
CUB-II, and then manually closing
the input will reset all active Safety
mode alarms.
6.5.1. High Discharge Trip Safety
Mode
The CUB-II will always try to prevent the
condensing unit's discharge pressure from rising
above a user-defined setpoint, called the dis-
charge trip setpoint. If the discharge pressure
ever rises above this setpoint, the CUB will enter
the High Discharge Trip Safety mode. This will
lock the compressor OFF, and cause the Circuit
State of the CUB to display Rack Fail in the E2
or Einstein and HHT status screens.
Alarm Conditions (Safety Modes)
Resetting a High Discharge Trip
Resetting a high discharge trip safety mode
can be done manually by closing the Alarm
Reset input on the CUB-II or by resetting the
High Discharge Trip alarm in the E2 or Einstein
alarm log.
You can also program the CUB-II to auto-
reset when the discharge pressure falls below the
discharge trip setpoint minus a user-defined dif-
ferential. This ensures the pressure will drop
well below the trip setpoint before re-starting the
compressor.
When using auto-reset, you may also set a
maximum number of auto-reset attempts. The
CUB will only attempt an auto-reset if it has not
already auto-reset the CUB a number of times in
the past hour equal to the user-defined maxi-
mum. If CUB's auto-reset maximum has already
been met, it will remain in High Discharge Trip
mode until it is manually reset.
6.5.2. Compressor Proof Fail Safety
Mode
If the CUB-II has a Compressor Proof input
configured, it can use this input to verify the
compressor is operating properly. Under normal
conditions, the CUB-II will expect the proof
input to mirror the state of the compressor at all
times (i.e., proof registers ACTIVE when the
compressor is ACTIVE, and INACTIVE when
the compressor is INACTIVE). If the proof input
does not mirror the value of the compressor state
for a period of time longer than a user-defined
period, the CUB-II will enter Proof Fail mode.
In Proof Fail mode, you may either choose to
program the CUB-II to shut down the compres-
sor until the failure is cleared, or to keep
attempting to activate/deactivate the compressor
as normal.
MultiFlex CUB-II and CUB-TD Software Overview • 19
Advertisement
Table of Contents
