Johnson Controls GVB Series User Manual

5586996-JSG-A-0120
25–50 Tons
Premier Rooftop Units
R-410A
LD26877
Table of Contents
Nomenclature ...................................................................... 4
Pre Start-Up Checklist ......................................................... 7
Start-Up ............................................................................... 9
Long Term Storage ......................................................... 9
Checking System Prior to Initial Start (No Power) ......... 9
Unit Checks (Power Applied) ....................................... 10
Initial Start-Up .............................................................. 16
Refrigerant Charge ............................................... 16
Checking Sub-Cooling and Superheat.................. 16
Leak Checking ...................................................... 17
Gas Heat Models .................................................. 17
Phase Monitor Adjustment .................................... 20
Commissioning Mode................................................... 20
Air Balancing Wizard .................................................... 20
Start-Up Wizard ............................................................ 24
Start-Up Wizard Sequence ................................... 26
Sequences of Operation .................................................... 30
Control Boards ............................................................. 30
Variable Frequency Drives (VFDs) ............................... 37
Unit Type ...................................................................... 38
Occupancy Mode ......................................................... 38
Morning Warm-up/Cool Down ............................... 38
Coast..................................................................... 38
Remote Safety Shutdown ............................................ 39
Low Voltage Monitoring ................................................ 39
Supply Fan Operation .................................................. 39
Supply Fan Alarm.................................................. 39
MZVAV Supply Fan ............................................... 39
SZVAV Supply Fan ............................................... 40
Redundant Supply Fan VFD ................................. 40
Cooling Operation ........................................................ 40
MZVAV Cooling Operation .................................... 40
SZVAV Cooling Operation ..................................... 42
Compressors and Refrigeration Circuits ............... 42
Compressor Staging Sequences .......................... 44
Condenser Systems and Fans.............................. 48
Dehumidication (Hot Gas Reheat) ...................... 49
Economizer ........................................................... 51
Heating ......................................................................... 52
Gas Heating .......................................................... 52
Electric Heating ..................................................... 56
Hydronic Heating .................................................. 56
MZVAV Heating Operation .................................... 56
SZVAV Heating Operation .................................... 57
Ventilation..................................................................... 58
Ventilation Sequences .......................................... 58
Low Mixed Air Temperature Limiting ..................... 58
Demand Control Ventilation .................................. 58
Continuous Ventilation .......................................... 59
Pre-Occupancy Purge........................................... 59
Humidification............................................................... 60
Humidication Sequence ...................................... 60
Exhaust System ........................................................... 60
Modulating Exhaust Fan ....................................... 60
Modulating Exhaust Damper with Fan .................. 60
External Control .................................................... 60
Return Fan ................................................................... 60
Return Fan Discharge Pressure ........................... 61
Supply Fan Airow Tracking.................................. 61
Energy Recovery Wheel .............................................. 61
Single Speed Energy Recovery Wheel ................. 61
Variable Speed Energy Recovery Wheel .............. 61
Ultraviolet Lights........................................................... 61
Smoke Control ............................................................. 62
Purge .................................................................... 62
Pressurization ....................................................... 62
Depressurize ......................................................... 62
START-UP & OPERATION

Johnson Controls GVB Series Specifications

General

Brand	Johnson Controls
Model	GVB Series
Category	Air Conditioner
Language	English