Honeywell DVD Recorder L Benutzerhandbuch

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The R7140 provides a pre-purge timing selectable from two 

seconds to 30 minutes with power applied and the R7140 

operating control indicating a call for heat: 

a. Running Interlocks, Pre-Ignition Interlocks, Burner 

Switch, Run/Test Switch, Lockout Interlocks and all 

microcomputer monitored circuits must be in the 

correct operating state.

b. The blower motor output, terminal 8, is powered to 

start the PREPURGE sequence. The PREPURGE 

timing for the R7140L does not begin until the High 

Fire Switch is closed.

c. The Pre-Ignition Interlock input must remain closed 

throughout PREPURGE; otherwise, control returns to 

the STANDBY state and holds (30 seconds) for the 

R7140G,M or safety shutdown for the R7140L occurs.

d. The Lockout Interlock or Running Interlock inputs 

(interlock circuit including Airflow Switch) must close 

by ten seconds into PREPURGE; otherwise, a 

recycle to the beginning of PREPURGE for the 

R7140G,M will happen or a safety shutdown for the 

R7140L occurs.

e. When PREPURGE timing is complete, the firing rate 

motor drives to the low fire position. If a damper 

motor is used (R7140M), jumpers J1 and J2 should 

be removed from R7140 subbase.

f. When the firing rate motor reaches low fire position, 

the Low Fire Switch, terminal 13, is energized to 

enter the Ignition Trial state.

1. Pilot Flame Establishing Period (PFEP):

a. With the firing rate motor at the low fire position:

(1) The pilot valve and ignition transformer, 

terminals 5, 6, and 18, are energized.

(a)The R7140G has an interrupted or intermit-

tent pilot valve, terminal 6, depending on the 

selection of configuration jumper 2.

(b) The R7140L has a 15-second interrupted 

pilot valve, terminal 6.

(c)The R7140M has an intermittent pilot valve, 

terminal 6.

(2) During PFEP, the Low Fire Switch must remain 

closed. If it opens, a safety shutdown occurs.

(3) The Pre-Ignition Interlock input is ignored 

throughout the Ignition Trial state.

b. Flame must be proven by the end of the 10-second 

PFEP (four if JR1 is clipped) to allow the sequence 

to continue. If flame is not proven by the end of 

PFEP, a safety shutdown occurs.

c. After five seconds, the ignition, terminal 18, is 

de-energized for early spark termination.

2. Main Flame Establishing Period (MFEP):

a. Terminal 7 is energized when the presence of flame is 

verified at the end of a 10-second Pilot Flame Estab-

lishing Period (PFEP) (four seconds if JR1 is clipped).

b. Terminal 5 is turned off 10 seconds after terminal 7 

is energized.

c. Terminal 6 action:

(1) R7140L: De-energized 15 seconds after terminal 

7 is energized.

(2) R7140G:

(a)Not turned off, or

(b)15 seconds after terminal 7 is energized and 

JR2 is clipped, or

(c)30 seconds after terminal 7 is energized and 

terminals 8 and 15 are jumpered and jumper 

JR2 is clipped.

(3)  R7140M: Remain energized as long as call for 

heat is present.

1. Fifteen seconds after the main valve terminal 7 is 

energized and flame is maintained, the R7140 goes to 

Run.

2. The firing rate motor releases to modulation 

(R7140G,L). Damper motor is energized (R7140M).

3. The R7140 is now in RUN and remains in RUN until the 

controller input, terminal 16 or 4 (model dependent), 

opens, indicating that the demand is satisfied or a limit 

opened.

The R7140 provides a 15-second POSTPURGE following the 

completion of the RUN period (call for heat ends). The blower 

motor output remains powered to drive all products of 

combustion and any unburned fuel from the combustion 

chamber. It also supplies combustion air to burn fuel being 

purged from the fuel line downstream of the fuel shutoff valve.

1. The main fuel valve and intermittent pilot valve, 

terminals 7 and 6, are de-energized and the firing rate 

motor is commanded to the low fire position to begin the 

POSTPURGE period.

2. After the 15-second POSTPURGE period is completed, 

the blower motor (terminal 8) is de-energized and the 

R7140 reenters Standby.

Do not use the Run/Test switch during the Pilot Flame 

Establishing Period for the R7140 when using Direct 

Spark Function, because it turns on the main gas 

valve, causing an accumulation of fuel in the burner.

The Run/Test Switch is located on the top side of the R7140, 

see Fig. 1. The Run/Test Switch allows the burner sequence 

to be altered as follows: