Mercoid DS-7000 Series User manual

Series DA/DS-7000 Bourdon Tube Pressure Switches
are SPDT snap-action switches that combine extremely
high sensitivity and repeatability with easily adjustable set
and reset points through non-interactive external adjust-
ments. These switches have visible calibrated dials for set
points and on-off indicators to indicate switch actuation.
DA models are equipped with two external adjustments.
One sets the high pressure operating point; the other sets
the reset point. Deadband or the difference between set
and reset points is adjustable over the full scale. DS mod-
els have a fixed deadband.
NOTE: The DS7300 has no status indicator.
INSTALLATION
The switch may be mounted in any position. Select a loca-
tion recommended by equipment manufacturer. Where
excessive vibration occurs, mount the switch remotely,
using an appropriate remote connection and mounting
bracket. See accessories, below.
ACCESSORIES
CAUTIONS:
Control movement must not be oiled. Do not overload.
Note electrical rating on name plate and be sure that total
current passing through the switch is within specified rat-
ing.
When testing a boiler or system, never exceed maximum
pressure rating on control or it may be seriously damaged.
Remove control if higher pressures are required.
Do not fail to use a siphon on steam where range is 35 lbs
(2413 mbar) or more.
Series DA/DS-7000 Bourdon Tube Pressure Switches
Specifications - Installation and Operating Instructions
Bulletin IN-523
1/4 N.P.T.
6-1/64
[152.8]
DIA.
7/8 [22.23]
ADJUSTMENT SCREWS
2-1/4
[57.15]
1-5/8
[41.28]
1/2 [12.7]
CONDUIT HOLE
5/8 [15.88]
MERCOID
CONTROL
PHYSICAL DATA
Pressure Range: Models range from 0 to 30” Hg (0 to
762.5 mm/Hg) Vac. to 800 to 8000 psig (55.16 to 551.6
bar).
Maximum Temperature: 180°F (82°C). For higher tem-
perature media applications, a remote connection or siphon
(pigtail) should be used.
Pressure Connections: 1/4″NPT standard; 1/2″NPT on
ranges 500 to 5000 psig and 800 to 8000 psig.
Housing: Pressed steel with transparent cover.
Wiring Connections: Three-screw type.
Wetted Parts: Same as Bourdon tube material (brass,
403SS or 316SS) on all ranges except 23K, 24K, and 9K,
which have carbon steel bottom connections.
Weight: 4 lb/1.8 kg (standard); 6 lb/2.7 kg (weatherproof);
8 lb/3.6 kg (explosion-proof)
Max. Pressure: Max. adjustment of operating range.
Mounting
Bracket Remote Connection
Pigtail
Siphon
Contact: Northeast Controls Incorporated
P.O. Box 275 - Upper Saddle River, New Jersey 07458
Tel: [phone] | Fax: [phone] | [email protected]
www.nciweb.net/dwyer

GENERAL PURPOSE CONTROLS, TYPES DA, DL, DR, DS
Mount control in any position. Do not twist the case when
installing. Use a wrench on the square part of the control
connection. On controls with operating Range No. 15S (500
to 5000 psi (34.47 to 344.75 bar)) or Range No. 16S (800
to 8000 psi (55.16 to 551.6 bar)), be sure the special seal-
ing nut (with Teflon®insert) is turned to the uppermost
threaded section of the 1/2″pressure connection. Apply a
flat open-end wrench to the flat side of the bottom pressure
connection when piping the control. After properly con-
necting the control, tighten the sealing nut to assure a leak-
proof connection.
FLANGED CASE CONTROLS
Mount by means of the three holes in the flange. Note:
Series D7030 when used for steam with operating ranges of
35 psi (2.413 bar) or higher, must be siphoned to prevent
live steam entering the Bourdon tube. With high-pressure
steam exceeding 100 psi (6.895 bar), use a remote con-
nection. (Note accessories on Page 1.)
Series D-7020 incorporate an orifice as standard in the
pressure connection to dampen surges or pulsations.
WEATHER-RESISTANT (RAINTIGHT)
NEMA 2, 3, TYPES N3DAW, N3DRW, N3DSW
These switches are supplied with flanged case, bottom con-
nection, for surface mounting.
WATERTIGHT AND WEATHERPROOF
NEMA 2, 3, 4, 5, TYPES DAW, DRW, DSW, C4DAW*,
C4DAW*, C5DSW*
These switches are supplied with flanged case, bottom con-
nection, for surface mounting only.
* Conforms to Canadian Standards Association requirements
EXPLOSION-PROOF TYPES DAH, DRH, DSH
Mount with mounting lugs attached to control housing.
WIRING
Wire in accordance with the National Electrical Code and
local regulations. For general purpose controls, use a short
piece of BX between the rigid conduit and the control so the
control will not be subjected to conduit expansion and con-
traction. Where the control is directly connected into the
load circuit, it should be connected into the hot side of the
line. Do not exceed electrical rating as stamped on the con-
trol nameplate. DS-7300 controls are equipped with a ter-
minal block. Field connection should be made to terminal
block pole in common with required pole of the control’s
switch. The color code is:
Black - Common
Blue - ON Hi
Red - ON Lo
Bulletin IN-523
Page 2
MOUNTING
HOLES (OPTIONAL)
1/2 NPT
9-7/8
BREATHER
(OPTIONAL)
5
3/4CONDUIT
CONNECTION
13/32DIA.
1/4NPT
7-3/4
3-1/2
Explosion-Proof
Types DAH, DRH, DSH
6-1/2DIA.
13/64
DIA.
BACK
CONNECTION
BOTTOM CONNECTION
DA24
DA34
DA44
DA23
DA33
DA43
Flange for Surface Mounting
HOLES FOR
FLANGE SCREWS
1/2CONDUIT
CONNECTION
6-1/64DIA.
1/4NPT
1-1/2
1/4
NPT
1-1/8
[«\«1
DA21
DA31
DA41
DA22
DA32
DA42
3
General Purpose
Types DA, DS, DR, DL
REAR FLANGE MOUNTING HOLES (3) 2-13/16
1/4 NPT
[\««1
7DIA.
ADJUSTMENTS 1/2
CONDUIT
HUB
GASKETED COVER
Weather-Proof
Types DAW, DSW, DRW

ADJUSTMENTS: HOW TO SET OPERATING POINT
Double Adjustment Types - Fully Automatic:
With double-adjustment switches (prefixed DA, DAH or
DAW), adjust the upper pointer “U” to set HIGH PRESSURE
POINT for switch operation and adjust the lower pointer “L”
to set LOW PRESSURE OPERATING POINT. The differ-
ence between the “U” and “L” pointers is the operating dif-
ferential between “on-off” switch operation.
Semi-Automatic Control with Manual Reset:
Models prefixed DR, DRH, DRW and with suffix L or U
(example: DR-7021-153U) have a single adjustment that
sets the operating point for automatic operation. A push-
button reset must be operated manually to restore the cir-
cuit to the original position after automatic operation.
Example: Type DR-7021-153L has a circuit that opens
automatically on a pressure rise to the pressure indicated by
the pointer on the scale; no matter how much the pressure
drops, the circuit will not re-close until the reset button is
operated. Suffix L denotes control will operate automati-
cally on an increase. Suffix U denotes control will operate
automatically on an decrease.
SINGLE ADJUSTMENT TYPES—FULLY AUTOMATIC:
Models prefixed DS, DSH, DSW, N3DSW are equipped with
a single adjustment. Differential is fixed (not adjustable). The
single pointer on the scale sets the pressure at which switch
operation occurs. Differential is listed in chart indicates
approximate fixed differential.
LOCKING DEVICE
When the control has been adjusted to desired range, the
locking bar may be inserted between the adjustment
screws with the slot passing over the projecting lugs. By
placing a sealing wire between the locking bar and the hole
in the lug protruding from the adjustment assembly, adjust-
ments cannot be tampered with.
For DRF, DAW, DRW, adjusting knob cover may be sealed
in place with sealing wire through cover bolt hole. For DAH,
sealing wire may pass through locking bar and hole in hub
above adjusting knobs.
DELRIN®BUSHED MOVEMENT “B”
Delrin®bushed movements prolong control life by alleviating
wear of metal surfaces due to excessive vibration and/or
pulsation. They also prolong switch life in environments
where corrosion may be a factor. Models with Delrin move-
ments are identified by the letter “B after the suffix number.
Examples: -153B, -153UB, etc.
*Delrin is a registered trademark of E. I. DuPont de Nemours & Co.
CONTROL NUMBER
Part of the control number (the fourth number in the sequence)
identifies the type of control case. Digit 1 of 7021, 7031, 7041,
denotes a plain case with bottom connection. Digit 2 of 7022,
7032, etc., denotes a plain case with back connection. Digit 3 of
7023, 7033, 7043, etc., denotes a flanged case with bottom con-
nection. Digit 4 of 7024, 7034, etc., denotes a flanged case with
back connection. (Digit 3 of 7321, 7331, 7341, etc., denotes her-
metically sealed snap switch.)
CIRCUITS (SWITCH OPERATION)
Suffix number after control number denotes switch action:
Suffix -153 designates SPDT; one circuit closes as other circuit
opens.
Suffix - 804 designates two SPDT switches; two close,
two open.
Double-Adjustment Types
Fully Automatic
Bulletin IN-523
Page 3
Semi-Automatic Types
with Manual Reset Delrin®Bushed Movement “B”
PIVOT POINT
BEARINGS,
TOP & BOTTOM,
BUSHED WITH DELRIN
SWITCH CARRIER
STOP POST SLEEVED
WITH DELRIN
DELRIN PIN
DELRIN PIN
BARLINK
DELRINBRUSHED
PIVOTAL END
BEARING &
CONNECTION
BAR PIN OF
DELRIN
Switch Indicator
Orange indicates
on high
U - Upper
Pointer
L - Lower
Pointer
Single
Adjustment
Switch
Operating
Indicator
Single Adjustment Types Fully Automatic
Adjustment
Reset

©Copyright 2001 Dwyer Instruments, Inc. Printed in U.S.A. 4/01 FR# 76-441853-00 Rev.1
Bulletin IN-523
Page 4
RANGES: TYPE DS
Single Adjustment
Fixed Differential
TYPE DA
Double Adjustment
Minimum Differential
Bourdon Tube
Material Range
Number
Adjustable
Operating Range
(PSIG)
SPDT
DA-7031-153
DAW-7033-153
DAH-7031-153
SPDT
DS-7231-153
DSW-7233-153
DSH-7231-153
(2) SPDT
DS-7231-804
DSW-7233-804
DSH-7231-804
SPDT
DS-7331-153
DSW-7333-153
DSH-7331-153
Brass
Bourdon Tube
403SS
Bourdon Tube
316SS
Bourdon Tube
316SS
Bourdon Tube
Carbon Steel
Bottom
Connection
2
3
1
3A
4
27
5
6
7
8
9
0-30” Hg Vac
1.0” Hg Vac-12 psig
1/8-15 psig
1/8-20 psig
1-35 psig
25” Hg Vac-50 psig
2-60 psig
5-100 psig
5-150 psig
10-200 psig
10-300 psig
9” Hg
4 psig
4 psig
4 psig
5 psig
8 psig
6 psig
9 psig
16 psig
16 psig
16 psig
3” Hg
1.5 psig
1.5 psig
1.5 psig
1.5 psig
2.5 psig
2 psig
2.5 psig
3.5 psig
4.75 psig
6 psig
2.5” Hg
1.25” psi
1.25 psig
1.25 psig
1.5 psig
2 psig
1.5 psig
2 psig
3.5 psig
4 psig
6 psig
5” Hg
3” psi
3 psig
3 psig
3 psig
3.75 psig
3 psig
3.75 psig
5.25 psig
6.75 psig
9 psig
25S
26S
5S
6S
8S
9S
9AS
10S
11S
12S
13S
15S
16S
30” Hg Vac-50 psig
30” Hg Vac-75 psig
2-60 psig
5-100 psig
10-200 psig
10-300 psig
40-350 psig
25-600 psig
50-1000 psig
100-1500 psig
300-2500 psig
500-5000 psig
800-8000 psig
12 psig
12 psig
9 psig
13 psig
15 psig
20 psig
19 psig
45 psig
95 psig
130 psig
260 psig
900 psig
1500 psig
3.5 psig
3.5 psig
3 psig
3.5 psig
4.75 psig
7 psig
7psig
12 psig
22 psig
35 psig
60 psig
200 psig
500 psig
3 psig
3 psig
2.5 psig
3 psig
4 psig
6 psig
6 psig
10 psig
20 psig
30 psig
50 psig
110 psig
180 psig
5.25 psig
5.25 psig
4.5 psig
5.25 psig
7.125 psig
10.5 psig
10.5 psig
18 psig
33 psig
52.5 psig
90 psig
300 psig
750 psig
26E
23E
6E
24E
9E
21E
22E
11E
13E
30” Hg Vac- 75 psig
5-75 psig
10-100 psig
10-150 psig
10-300 psig
30-400 psig
75-800 psig
100-100 psig
200-2500 psig
10 psig
8 psig
10 psig
11 psig
28 psig
52 psig
120 psig
190 psig
400 psig
3.5 psig
4 psig
3.5 psig
4.5 psig
8 psig
12 psig
25 psig
35 psig
75 psig
4 psig
2.5 psig
4 psig
3 psig
6 psig
10 psig
17 psig
30 psig
95 psig
5.25 psig
6 psig
5.25 psig
6.75 psig
12 psig
18 psig
37.5 psig
52.5 psig
112.5 psig
SPDT
DA-7021-153
DAW-7023-153
DAH-7021-153
SPDT
DA-7041-153
DAW-7043-153
DAH-7041-153
SPDT
DA-7041-153
DAW-7043-153
DAH-7041-153
SPDT
DS-7221-153
DSW-7223-153
DSH-7221-153
SPDT
DS-7241-153
DSW-7243-153
DSH-7241-153
SPDT
DS-7241-153
DSW-7243-153
DSH-7241-153
(2) SPDT
DS-7221-804
DSW-7223-804
DSH-7221-804
(2) SPDT
DS-7241-804
DSW-7243-804
DSH-7241-804
(2) SPDT
DS-7241-804
DSW-7243-804
DSH-7241-804
SPDT
DS-7321-153
DSW-7323-153
DSH-7321-153
SPDT
DS-7341-153
DSW-7343-153
DSH-7341-153
SPDT
DS-7341-153
DSW-7343-153
DSH-7341-153
Adjustable
Operating Range
(PSIG)
Adjustable
Operating Range
(PSIG)
Range
Number
Range
Number
Adjustable
Operating Range
(PSIG)
Range
Number
23K
24K
9K
5-75 psig
10-150 psig
10-300 psig
8 psig
11 psig
28 psig
4 psig
4 psig
8 psig
2.5 psig
3 psig
6 psig
6 psig
6 psig
12 psig
Two SPDT Switches*
Electrical Ratings See Code F See Code D See Code E See Code D See Code K
D
E
F
G
K
Code AC Capacity ELECTRICAL RATINGS
DC Capacity
120V 240V 480V
15A 15A NA
15A 15A 15A
12A 10A 5A
120V 240V
.5A .25A
NA NA
.5A .25A
5A @ 250 AC. Resistive & Inductive; 30V DC Resistive
5A @ 125/250 AC, Resistive; 30V DC Resistive
AC Horsepower
120V 240V
1/8 1/4
1/4 1/2
1/4 1/2
Circuit
Suffix No.
-153
-804
*Note: Minimum differentials increase when using multiple circuits. Controls using #804 circuits in ranges over
35 psig have 30% higher minimum differentials; ranges under 35 psig are not available in Code F.
Switch Action on Pressure/Temperature Increase
SPDT: one OPENS as one CLOSES
(2) SPDT: two OPEN as two CLOSE
Electrical Rating Code
D-7000 D-2000 D-7300
D E K
F* G
Contact: Northeast Controls Incorporated
P.O. Box 275 - Upper Saddle River, New Jersey 07458
Tel: [phone] | Fax: [phone] | [email protected]
www.nciweb.net/dwyer