Steffes HPB22 Owners Manual - Manual (Page 7)

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C. HPB CONTROL DEVICES & SAFETY LIMIT DEVICES
(TABLE 2)
DEVICE CONDITION
CATEGORY NAME LOCATION MONITORED ACTION
Control Outdoor Air Outside in a protected Outdoor Air Signals to the charge control
Devices: Temperature location providing Temperature system to set core charge
Sensor representative outdoor level in relation to outdoor
air temperatures. (See temperatures (SeeTable1).
Outdoor Sensor Placement
in Installation Section)
Charge Control HPB Electrical Section Core Temperature Maintains core tempera-
Thermostat ture level in response to the
outdoor air temperature
sensor.
Low Temperature Supply Duct (minimum Supply Air Modulates HPB mixing
Duct Sensor of 3' downstream from Temperature damper to maintain
HPB supply discharge) comfortable supply air
temperature (Stage 1
heat call).
Air Discharge Air Discharge Outlet Port HPB Discharge Modulates HPB mixing
Controller Air Temperature damper to maintain
maximum HPB dis-
charge air temperature
(Stage 2 heat call).
130 o Low Core See Figure 10 Core Temperature De-energizes HPB
Temperature blower below preset
Switch temperature
(See Table 3).
Safety Core Charging High HPB Limit Bar (See Core Temperature De-energizes HPB
Devices: Limit Switches: Figure 9) resistance heating
(3) each HPB11B elements.
(4) each HPB15B
(6) each HPB22B
Air Discharge Air Discharge Outlet HPB Air Discharge De-energizes HPB
High Limit Port Temperature blower when discharge
air exceeds 190
o F.
Slam Gate Air Discharge Outlet HPB Air Discharge At air discharge
Port Temperature temperature of 212 o F,
fusible melt link re-
leases slam gate,
positively blocking
discharge air. All HPB
electrical functions de-
energized.