Table 21 — Compressor MUX Board Voltages
| COMP | VOLTS | RANGE |
| None | 1.86 | 1.50 < V < .95 |
| 1 | 2.88 | last val < = V < 2.95 |
| 2 | 3.59 | last val < = V < 3.68 |
| 1,2 | 4.44 | last val < = V < 4.55 |
| 3 | 5.13 | last val < = V < 5.25 |
| 4 | 5.71 | last val < = V < 5.85 |
| and CMP4 is on |
| | |
| 1,3 | 5.85 | last val < = V < 5.99 |
| 1,4 | 6.39 | last val < = V < 6.51 |
| and CMP4 is on |
| | |
| 2,3 | 6.36 | last val < = V < 6.54 |
| 2,4 | 6.87 | last val < = V < 7.03 |
| and CMP4 is on |
| | |
| 1,2,3 | 6.99 | last val < = V < 7.15 |
| 1,2,4 | 7.46 | last val < = V < 7.63 |
| 3,4 | 7.94 | last val < = V < 8.11 |
| 1,3,4 | 8.45 | last val < = V < 8.58 |
| 2,3,4 | 8.81 | last val < = V < 8.99 |
| 1,2,3,4 | 9.26 | V > 8.99 |
CONDENSER WATER FLOW — This is an optional switch that can be used with the OMNIZONE™ controller. A thermal dispersion flow switch detects water flowing past the sensor element and closes normally open contacts that energize a relay with normally open contacts to the unit controller. If no flow switch is installed, a jumper must be in place to indicate that there is water flow all the time in order for the economizer and compressors to operate. A configuration decision is used to indicate if a flow switch is installed and disable alarms from the flow switch. When the flow switch is installed, the controller will check for water flow when flow is requested for unit operation. The controller will also test or to see if there is water flow when the unit is not operating. If there is no flow when the unit is operating or if there is flow when the unit is not operating, the warning relay will energize and the yellow light will be lit. If only loss of flow indication is desired, the configuration for the flow switch may be set to no and the controller will only energize the warning relay and turn on the yellow light if there is a loss of flow while the unit is in operation.
DIRTY FILTERS INPUT — This air pressure delta switch is factory installed in the 50XJ unit. It receives 5 vdc from the unit controller and monitors air pressure delta across the return air filters. Switch is normally open, with manually adjustable setting at the switch between 0.5 to 1.5 in. wg. Upon closure, controller should wait to assure closure for minimum 1 minute, and then indicate an alarm both via its Alarm Output and via communications. However, all other unit operation should remain normal.
A phase loss reversal switch may be installed in the unit to detect over, under voltage conditions and phase loss or reversal. Upon switch opening, the controller outputs will be forced to off with safety forces, the alarm output will close and the red Alarm light will be lit. A system alarm will be generated and displayed on the unit keypad. Unit reset is automatic when the voltage and power phases have been restored.
ECONOMIZER COIL FREEZE PROTECTION SWITCH — This switch is installed in the 50XJ unit when the economizer coil is provided. In the event the freeze protection switch contacts open, the ventilation request output will be closed for 15 minutes and the Warning light will light. If the freeze protection switch contacts are still open after 15 minutes, the supply fan will be stopped, all compressor cooling will stop, the economizer valve will open to 100%, the pump request output will remain on, and the Alarm light will light. This will maintain condenser water flow through the coil to prevent freezing the coil while stopping all other operations that could have contributed or will be affected by the freeze condition. Unit reset is automatic when the contacts on the freeze protection switch close again. The contacts on the freeze protection switch open below 37 F.
SUPPLY FAN STATUS — Supply fan status is determined by the duct static pressure sensor. If the fan is operating and a fan speed signal is sent to the variable frequency drive, the duct static pressure must become greater than the supply fan status high set point (SETPT01) for the supply fan status software point to turn on. When the duct static pressure becomes lower than the supply fan status low set point, the supply fan status will indicate OFF. If at any time the commanded state of the supply fan does not agree with the supply fan status for more than a minute, a supply fan status warning will be issued and the warning light will be lit.
COMPRESSOR STATUS — Compressor status is determined from the compressor MUX voltage input to the OMNIZONE controller. If at any time the compressor status indicates off for more than 30 seconds when the compressor commanded state is on, the compressor will be turned off with a safety force and the controller will try to start the compressor after five minutes. If the compressor status does not indicate on for more than 30 seconds then the compressor will be turned off again with a safety force for ten minutes. The controller will then try to restart the compressor a second time. If the compressor status does not come on within 30 seconds the compressor will be turned off for 15-minutes this time. After the 15-minute delay the controller will try to restart the compressor for a third time. If the compressor does not start it will be locked out for this operating cycle and will not be restarted until the OMNIZONE controller goes through an off cycle where the cooling and supply fan are shut down. When the compressor is going through the three restarts or when it is locked out the Warning light will be lit and the specific compressor alarm will be indicated on the display and via communications. The three strikes compressor test is reset automatically if the compressor status comes on while the compressor is on.
