York Sun Select YV28 - Page 4

Supply air drive adjustment.......................................... 83
Operation.............................................................................. 84
Cooling sequence of operation.................................... 84
Compressor Operation.................................................. 84
2 Stage Cooling........................................................ 84
4 Stage Cooling........................................................ 84
Gas heat sequence of operation.................................. 84
Two Stage gas heat Ignition Control Board
function............................................................................ 85
Ignition Control Board on standby........................ 85
Pressure switch proving.......................................... 85
Pre-purge.................................................................. 85
Ignition trial period.................................................. 85
Flame stabilization period....................................... 85
Main Burner operation............................................ 85
Post Purge................................................................. 86
Lockout...................................................................... 86
High temperature limit switch................................ 86
Roll-out switch.......................................................... 86
Power interruptions................................................. 86
Flame present with gas off..................................... 86
Welded gas valve relay response........................... 86
Cooling start-up................................................................... 87
Cooling pre-start checklist............................................ 87
Operating the unit......................................................... 87
Post-start checklist......................................................... 87
Gas heat start-up................................................................. 88
Gas heat pre-start checklist.......................................... 88
Operating instructions.................................................. 88
Gas heat post-start checklist........................................ 88
Shutting down the unit................................................. 88
Checking Gas Heat Input.................................................... 90
To determine the rate of gas flow at Second Stage
(full input)........................................................................ 90
To determine the rate of gas flow at First Stage
(minimum input)............................................................. 90
Manifold Gas Pressure Adjustment............................. 91
Two Stage........................................................................ 91
Adjustment Of Temperature Rise................................ 91
Burners/Orifices Inspection/Servicing........................ 92
Charging tables.................................................................... 93
Smart Equipment™ unit control board............................. 96
Four-stage board............................................................... 101
Cable recommendations............................................. 103
Start-up sheet..................................................................... 104
Installation Manual: YORK
®
Sun
™
Select YV28 to YV50
4
Johnson Controls Ducted Systems