Nilfisk-Advance 56508769, Руководство по обслуживанию

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8 - FORM NO. 56043123 - SR 1900
SECTION 4 — HEATING SYSTEM
Note: Refer to Section 2 — Know Your Machine and the schematics in Section 6 — Appendix.
GENERAL SYSTEM OVERVIEW
The SR 1900 cab heating system uses an electronic Heater Control Assembly (15) to direct the appropriate amount of engine coolant to the Heater Core (9) in the
Heater Air Box Assembly (10) . The Blower Assembly (8) in the Heater Air Box Assembly blows fi ltered air through the Heater Core to provide warm air to the cab.
A four-port bypass butter fl y valve in the Heater Control Assembly, run by a small electric motor, controls the coolant fl ow to the Heater Core. The Heater
Temperature Control (4) in the cab controls the voltage to the valve motor, and uses a feedback potentiometer to sense the position of the butter fl y valve.
ELECTRICAL CIRCUIT OVERVIEW
Heater Blower Motor
The following conditions must be met for the blower motor to function:
Positive (+) Voltage
The key switch

(S1) must be in either the accessory or ignition position to p12 VDC (GRN/BLU wire) to the 20A circuit breaker CB4 .
Circuit breaker

CB4 must be closed to p12 VDC (VIO wire) to the control side (coil) of the HVAC Relay K8 .
The 20A circuit breaker

CB9 must be closed to provide voltage (RED/VIO wire) to the input load side of the HVAC Relay K8 .
HVAC Relay

K8 must be closed to p12 VDC (VIO/GRAY wire) to the positive terminal on the Fan Switch S30 .
The Fan Switch

S30 must be set to the Low (YEL wire), Medium (RED wire) or High (ORN wire) position to p12 VDC to the corresponding terminal on
the Blower Motor M6 .
Negative (–) Voltage
The Blower Motor M6 must be connected to battery negative (BLK wire).
The control side (coil) of the HVAC Relay K8 must be connected to battery negative (BLK wire).
Heater Temperature Control
The following conditions must be met for the heater temperature control to function:
Positive (+) Voltage
The key switch must be in either the accessory or ignition position to p12 VDC (GRN/BLU wire) to the 20A circuit breaker

CB4 .
Circuit breaker

CB4 must be closed to p12 VDC (VIO wire) to the control side (coil) of the HVAC Relay K8 .
The 20A circuit breaker

CB9 must be closed to provide voltage (RED/VIO wire) to the input load side of the HVAC Relay K8 .
HVAC Relay

K8 must be closed to p12 VDC (VIO/GRAY to RED wire) to the Heater Temperature Control E1 .
Negative (–) Voltage
The Heater Temperature Control E1 (BLK wire) must be connected to battery ground.
The control side (coil) of the HVAC Relay K8 must be connected to battery negative (BLK wire).