Harwil Q-8N Installation Manual

MODEL Q-8

Q-8N

INSTALLATION INSTRUCTION SHEET

HARWIL CORPORATION

541 KINETIC DRIVE, OXNARD, CA 93030

TEL: [phone] FAX: [phone]

EMAIL: [e-mail]

GROMMET ‘A’

GROMMET ‘AA’

GROMMET ‘B’

GROMMET ‘C’

LEADSCREW

LEADSCREW NUT

ADJUSTING SPRING

BODY

1¼” x 1” BUSHING

SUPPLIED

STRAIN RELIEF NUT

COVER
4 RETAINING SCREWS
(NOT SHOWN)
“F” COVER

MICROSWITCH 15A SPDT
WITH 3 SLIP-ON TERMINALS
DRY CIRCUIT SPDT 0.1A 125 VAC
MICROSWITCH

MICROSWITCH BRACKET
WITH SPRING LEVER

2 SCREWS
2 NUTS
2 SPLIT LOCKWASHERS
1 PLAIN WASHER

O-RING

2 SCREWS

SEAL SHAFT ASSEMBLY
SUPPLIED ONLY COMPLETE WITH
A) SEAL SHAFT
B) DIAPHRAGM
C) DIAPHRAGM WASHER
D) FEED THRU SHAFT
E) PIVOT PIN
F) CAP (SONICALLY WELDED)

5D

NOTE: SEAL SHAFT MUST BE
GRIPPED DURING REMOVAL OR
INSERTION OF DRAG DISK ARM.
FAILURE TO GRIP SHAFT SECURELY
WILL CAUSE LEAKAGE OF INTERNAL
ELASTOMER SEAL.

DRAG STRIP
CLAMP WASHER
DAMPENER WASHER
SCREW x 3/8” LG
2 PLAIN WASHERS
SPLIT LOCKWASHER
FLOAT WASHER

2D

TURBULENT
FLOW REDUCTION

MOUNT IN
THREE POSITIONS

DRAG DISK ARM #1 (SMALL)
DRAG DISK ARM #2 (MEDIUM)
DRAG DISK ARM #3 (LARGE)

IMPORTANT: DO NOT APPLY TORQUE TO
DRAG DISK ARM SINCE IT MAY BE
UNTHREADED FROM SEAL SHAFT (A).

SCREW

DRAG DISK #1 (SMALL)
DRAG DISK #2 (MEDIUM)
DRAG DISK #3 (LARGE)

FLEXIBLE DRAG STRIP ASSEMBLY IS
AVAILABLE TO REPLACE DRAG DISK
AND DRAG DISK ARM.

PARTS LIST

FLUID FLOW SWITCH

ULTRA RELIABLE SINCE 1956 P. 1

HARWIL CORPORATION

541 KINETIC DRIVE, OXNARD, CA 93030

MODEL Q-8

Q-8N

TEL: [phone] FAX: [phone]

EMAIL: [e-mail]

INSTALLATION AND OPERATING INSTRUCTIONS

The Q-8 fluid flow switch is supplied with a 1¼” x 1” PVC TT bushing threaded in place with 2 to 3 wraps of
Teflon tape, which must be intact or renewed if bushing and switch are separated before assembly. Care must be
exercised when threading the PVC bushing into plastic or metal fittings. Apply a minimum of 2 to a maximum of
3 wraps of Teflon tape to threads of bushing - this is especially important if the unit is to be used in metal fittings
where coarse METAL THREADS could gall plastic if not lubricated. The plastic bushing CAN BE CRACKED if the
main body of the flow switch is tightened into it FIRST. Cracking will not occur if the bushing is FIRST tightened
into the pipe or tank fitting and THEN the Q-8 body is tightened into the bushing.

1. Teflon tape the thread and tighten plastic bushing into pipe or tank fitting.

2. Teflon tape the thread and tighten Q-8 switch into PLASTIC bushing by applying wrench to hexagon section.
Repeat steps 1 and 2 until ARROW on body points in the DIRECTION OF FLOW and threads are leak tight.

3. Inspect to make sure drag disk does not touch opposite wall of small diameter pipe.

Plumbers’ tools such as pipe wrenches are not recommended. If possible, use a “Rigid” type wrench where the
smooth jaws closely fit the hexagon section.

ELECTRICAL WIRING

1. Remove gland nut, grommet, and switch cover.

2. Strip outer jacket of electrical cord back approxi­mately 1¼”. Strip insulation from individual con­ductors back approximately ¼”

3. Slip-on terminals are supplied with each switch. Re­move from switch terminals and crimp on or solder
to electrical leads.

4. Feed electrical cable through gland nut, grommet,

1¼”

¼”

Fig 1: Wiring schematic for power applied to load when
flow is less than set point (power to load interrupted when
flow increases to above set point).

Decreasing flow moves actuator in direction shown.

DECREASING FLOW MOVES
ACTUATOR IN DIRECTION
SHOWN

LOAD

and switch cover as shown.

5. Apply slip-on terminals to appropriate contacts of
microswitch. Slide cover down cable and fasten to
body of switch with four (4) screws provided. Slide
grommet down cable until outer jacket is level with
small end of grommet. Push grommet into tapered
end of cover. Hold cable jacket to prevent rotation
and thread gland nut firmly onto cover.

Fig 2: Wiring schematic for power applied to load when
flow is greater than set point (power to load interrupted
when flow decreases to below set point).

Increasing flow moves actuator in direction shown.

INCREASING FLOW MOVES
ACTUATOR IN DIRECTION
SHOWN

LOAD

MICROSWITCH

NC

NO

COM

HOT

ULTRA RELIABLE SINCE 1956P. 2

LINE

MICROSWITCH

NC

NO

HOT

COM

LINE