Ashcroft B700 Instructies voor installatie en onderhoud - Pagina 2

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Installation and Maintenance Instructions for

B400 & B700 ASHCROFT

Switches for Pressure Control

B400 Series standard – one

B700 Series standard – two

permanent plug. NEMA 7 & 9 enclosures require proper conduit

seals and breathers as per the National Electrical Code.

B400 & B700 Series – XJL variation – two

holes with two

⁄

˝ to

⁄

˝ NPT reducing bushings.

B400 Series – XJK variation – two

B400 SERIES

SPDT – Wire directly to the switch according to circuit require-

ments. On controls with pilot lights wire lights according to cir-

cuit diagram on inside of cover. See special wiring instruction

tag for single switches with two pilot lights and dual switches

with one or more lights.

2 SPDT – Dual switching elements consist of two SPDT switch-

es mounted together in a bracket. Switches are calibrated to

have simultaneous operation within 1% of range either on

increasing or decreasing pressure but not in both directions.

Wire directly to the front and rear switch according to circuit

requirements. Leads are provided on rear switch color coded as

follows:

Common

– White

Normally Closed – Red

Normally Open

– Blue

See SPDT instructions for pilot light hook-up.

When hermetically sealed switch elements(s) are supplied, the

lead color coding is as follows:

Common

– White

Normally Closed – Red

Normally Open

– Blue

B700 SERIES

SPDT – Wire directly to the switch according to circuit require-

ments.

2 SPDT – Wire to front switch terminal block (left) and rear

switch terminal block (right) as marked. Strip insulation

insert in proper terminal connector and tighten clamping screw

to secure.

ADJUSTMENT OF SETPOINT

B400 & B700 Series – A single setpoint adjustment nut (

located centrally at the bottom on the inside of the enclosure.

For accurate setpoint calibration, mount the switch on a cali-

bration stand, a pump or catalog No.1305 deadweight gauge

tester. A suitable reference standard such as an Ashcroft

Duragauge or Test Gauge is necessary to observe convenient

changes in pressure.

As received, the pressure switch will normally be set to

approximately 90% of the indicated range. Pressurize the

system to required setpoint and turn the adjustment nut until

switch changes mode. Direction of turning is indicated on a

All sales subject to standard terms and conditions of sale. I&M009-10008-10/00 (250-2246E) 06/15

Snap Action

⁄

˝ NPT conduit hole right side.

⁄

˝ N PT conduit holes with one

⁄

˝ NPT conduit

⁄

˝ NPT conduit holes.

TERMINAL BLOCK

SWITCH A

TERMINAL BLOCK

SWITCH B

label affixed to the inside of the control enclosure. When set-

point has been achieved raise and lower pressure to insure that

setpoint is correct.

Once setpoint has been determined, tighten setpoint locking

SETPOINT LOCKING SCREW (B400 ONLY)

screw using a

setpoint locking screw only needs to be hand tight.

When performing calibration or changing the setpoint, the setpoint

locking screw should be loosened before turning the setpoint

adjusting nut. Once calibration is complete, re-tighten the set-

point locking screw.

After installation of the control replace cover to insure electrical

safety and to protect internal parts from the environment.

B450 and B750 VARIABLE DEADBAND SWITCHES

Deadband is varied by rotating the wheel on the precision

switch. When viewed from the front of the enclosure, rotation to

the left increases deadband – rotation to the right decreases

deadband. Letters on the wheel may be used as a reference.

Deadbands obtainable will vary from 0.5% to 9% of pressure

range depending on range segment and type of diaphragm.

ADJUSTMENT OF SETPOINT

As received, the pressure switch will normally be set to approxi-

mately 90% of range. Rotate the wheel on the MICRO SWITCH

all the way to the right; this will provide smallest deadband.

Pressurize the system to the required setpoint and turn the

adjustment nut until the switch changes mode. Lower the

pressure to reset the switch. Rotate the wheel on the MICRO

SWITCH until the desired deadband is obtained. The upper

setpoint will be changing upward with this adjustment. Lower

⁄

˝,

the pressure to reset the switch. Then increase the pressure to

the desired setpoint and turn the adjusting nut until the switch

changes mode. Lower the pressure and check resetpoint and

deadband.

Note – As indicated above, adjustment of setpoint is made by

⁄

˝) is

use of

screws and bracket adjusting screw are factory sealed

and should not be tampered with.

Note – Since vacuum models are already above setpoint at

atmosphere, the Normally Open (NO) circuit will be

closed as received.

Recommended Practices

Ashcroft recommends regular inspection of the operation and

setpoint of the switch in critical applications to prevent issues

that could cause severe damage to personnel or property.

˝ allen (hex) wrench. Do not over torque;

⁄

˝ nut. Precision switch element mounting

Setpoint

Locking

Screw