Greenheck DGK (468695) - Manual (Page 10)

10
IMPORTANT
Setting the maximum firing rate during mild weather
conditions may cause the high limit to trip out during
extreme conditions requiring manual resetting.
Maxitrol Series 14
Low fire time delay setting
(75% of maximum)
Remove the wire from Terminal 4
to send the unit to maximum fire
Clockwise rotation increases the temperature rise,
counterclockwise rotation decreases the temperature
rise.
The minimum setting for the maximum fire rate may be
higher than required. This is acceptable. The burner will
modulate as needed. While monitoring the unit’s temperature rise, set the
maximum firing rate by adjusting the Combination
Valve or Regulator for respective housing sizes
(shown to right) until the designed temperature rise
is achieved. After setting the maximum firing rate,
reconnect the wire to the amplifier.
3. FOR DGK-H25 ONLY: Check the pilot gas pressure.
The recommended gas pressure is 3 in. wg.
Adjust the pilot gas regulator as needed. The
location of the pilot regulator adjustment is shown on
the pilot valve/regulator image below.
Rotate the adjustment screw CW to increase the
pilot flame and rotate the screw CCW to decrease
the pilot flame.
4. Set the Low Fire Time Delay: Set the low fire time
delay to 75% of its maximum setting. See Maxitrol
Series 14 (pictured below) for the location of the time
delay setting.
The low fire time delay must be set high enough to
provide at least 15 seconds of low fire while the unit
tries to light.
5. Set the Maximum Firing Rate: Monitor the unit’s
actual temperature rise by placing a thermocouple in
the unit’s inlet and a second in the discharge, three
duct diameters downstream of the burner.
Send the unit to maximum fire by disconnecting and
isolating the wire connected to Terminal 4 on the
Maxitrol amplifier shown.
“ W.C.
“ W.C.
“ W.C.
F
PSI
“ W.C.
“ W.C.
MAX BTU/HR
BTU/H MAX
NORMAL MANIFOLD
PRESSURE
PRESSION D’ADMISSION
NORMALE
MIN GAS
PRESSURE
PRESSION DE GAZ
MIN BURNER
PRESSURE DROP
PERTE MIN DE PRESSION
DANS LE BRULEUR
TYPE OF GAS
NATURE DU GAZ
MIN BTU/HR
BTU/H MIN
MIN GAS PRESSURE
FOR MAX OUTPUT
PRESSION DE GAZ MIN
POUR PUISSANCE MAX
MAX BURNER
PRESSURE DROP
PERTE MAX DE PRESSION
DANS LE BRULEUR
MAX GAS
PRESSURE
PRESSION DE GAZ
MAX
DESIGN ∆T
∆T NORMALE
EQUIPPED FOR
CONCU POUR
SCFM “ W.C.
EXTERNAL STATIC PRESSURE
PRESSION STATIQUE EXTERIEURE
AGAINST
CONTE
Direct Gas Nameplate
NOTE
Do not set the burner maximum firing rate based on gas
pressure. It should be set based on the unit’s designed
temperature rise shown on the direct gas label.
Pilot Regulator
adjustment screw
DGK-H25 Pilot Valve/Regulator
DGK-H15
Combination Valve
Maximum firing rate adjustment
DGK-H25 Regulator
Model DGK Make-Up Air
®