Description of Operation
Table 8: UVC state names and numbers
Normal UVC modes | State names |
| State numbers |
| ||
Decimal | ASCII | Hex | ||||
|
|
| ||||
OFF | OFF | 9 | 9 | 57 | ||
Night purge | Night Purge | 8 | 8 | 56 | ||
Fan only | Fan Only | 10 | A | 65 | ||
Emergency heat | Full Heat | 7 | 7 | 55 | ||
Cant Heat | 13 | D | 68 | |||
|
| |||||
|
| Heat | 5 | 5 | 53 | |
| Heat | Cant Heat | 11 | B | 66 | |
|
| Low Limit | 14 | E | 69 | |
|
| EconMech | 1 | 1 | 49 | |
Auto |
| Mech | 2 | 2 | 50 | |
| Cool | Econ | 3 | 3 | 51 | |
| DA Heat | 4 | 4 | 52 | ||
|
| |||||
|
| Cant Cool | 12 | C | 67 | |
|
| Low Limit | 15 | F | 70 | |
WARNING
Off mode is a “stop” state for the unit ventilator. It is not a “power off” state. Power may still be provided to the unit.
OFF Mode (State 9)
Off mode is provided so that the UVC can be forced into a powered OFF condition. OFF mode is a “stop” state for the unit ventilator; it is not a power off state. OFF mode consists of a single UVC state: OFF [9].
When OFF mode becomes active, the UVC stops all normal heating, cooling, and ventilation (OA damper is closed), and fan operation ends. The UVC continues to monitor space conditions, indicate faults, and provide network communications (if connected to a network) in the OFF mode while power is maintained to the unit.
While in OFF mode, the UVC does not maintain DA temperatures. If the space temperature drops below EHS while in the OFF mode, the UVC is forced into the Emergency Heat mode (see “Emergency Heat Mode (Super State)” on page 16).
The space lighting output continues to operate based upon the current occupancy mode.
Note – Special purpose unit modes such as Purge, Pressurize, and
Figure 7: Off state diagram
OFF
9
UVC Mode = OFF
UVC Mode ≠ OFF
Transition point
14 | McQuay OM 751 |
