CONSTRUCT AN AC OVERVOLTAGE
PROTECTOR
By Dink Stockert, WA5LNL1
This AC Over-Voltage Protector
[OVP] is designed to protect your repeater from spikes and over-voltage
[lightning] coming in from your AC utilities. The OVP is good for 15 to 20 amps
at 120 VAC. The OVP box is equivalent to a PolyPhaserŠ
power line protector [pldo-120us20a: about $350].
Construction inside a metal box is best. A #6
solid copper wire should attach to the box to earth ground to make it
work! The OVP is made to hang on the wall, then feed your repeater cabinet. Use
a copper (Cu) lug, remove the paint under the lug and apply a layer of NoaloxŠ
anti-oxidant joint compound under the lug. Please see the photos for
construction details.
Inside your repeater cabinet you should have
another power strip (maybe an Iso-barŠ) with OVP. Always
have more than one protector in series. All wiring should be done with #12
copper. The AC cord should be a minimum # 12 gauge. The main coils are wired on
1/2"dia. PVC pipe x 8 1/4" long with 2" screws to hold off the
coil forms. Wind 59 turns of #12 Cu and leave extra wire at each end for
hookup. Use the 130vac 23mm size MOVS. Mount (2) MOVS* per leg [H to N, N
to G, H to G] and (3) MOVS on the output of the EMI filter.
The EMI filter needs to have a [bare] #12
cu. wire soldered from its metallic case to ground. Fusing at 15A would be
better than 20A if you do not need the extra power. Making coils [5 to 7 turns,
1/4" diameter] with left over wire between hookups never hurts. Lightning
gets dizzy in the coils and quits!
Total costs =$52.50 +\ - your junk
box parts
*MOVS wear out with time and even faster
with only minor spikes. So if you are
using an OVP that is 5 years old and not blown up; change the MOVS.
TranszorbsŠ do not wear out and
clamp voltages accurately with no over shoot.
If youÕve got the bucks, you can substitute a
General Semiconductors TranszorbŠ [#587b151, 15A, which
will blow a 15A fuse (and not blow up)
PARTS LIST
1. 1 Pull-Box,
10"x10"x4", Hubbell SC101004, [Lowe's]
2. 1 2-socket, surface-mount
steel electrical box [Lowe's]
3. 1 Steel outlet cover
[Lowe's]
4. 1 Dual 20A AC outlet, gray
color – commercial grade [Lowe's]
5. 1 AC cord +plug #12 gauge
(Buy an extension cord and cut the outlet off).
6. 1 15A/20A ceramic 3AG fuse
+ fuse holder [Hosfelt , 31-774, 342014A]
7. 1 EMI filter,
20A [Hosfelt 927-188]
8. 2 Capacitor, .01uF @ 1.6Kv
[Digikey 495-1372-ND]
9. 1 17 in. PVC ,
1/2" [Lowe's]
10. 2 Ground lugs for
#6Cu. [Lowe's]
11. 1 AC wire clamp [Lowe's]
12. 1 1/2" steel nipple and 2 nuts to secure
outlet box [Lowe's]
13. 1 Yellow wire nut
[Lowe's]
14. 4 RF Chokes, ~ 0.12 mH
; 7 turns #12 insulated solid copper house wire, wound on ¼Ó
drill. (L1, L5 black wire, L2, L6 white wire).
14. 2 RF Chokes: ~ 10.24 mH2;
59 turns #12 insulated solid copper house wire, wound on 13/16Ó o.d. white PVC.
(L3 back wire, L4 white wire). 22 feet of wire required for each coil.
15. 22 ft. white #12 Cu solid wire [Lowe's]
16. 9 MOVS :130vac/150vac,
quarter size,23mm [Hosfelt V150LA20B]
HOME
CONSTRUCT AN AC OVERVOLTAGE PROTECTOR BACK
By Dink Stockert, WA5LNL1
This AC Over-Voltage
Protector [OVP] is designed to protect your repeater from spikes and
over-voltage [lightning] coming in from your AC utilities. The OVP is good for
15 to 20 amps at 120 VAC. The OVP box is equivalent to a PolyPhaserŠ
power line protector [pldo-120us20a: about $350].
Construction inside a metal box is best. A
#6 solid copper wire should attach to the box to earth ground to make it
work! The OVP is made to hang on the wall, then feed your repeater cabinet. Use
a copper (Cu) lug, remove the paint under the lug and apply a layer of NoaloxŠ
anti-oxidant joint compound under the lug. Please see the photos for
construction details.
Inside your repeater cabinet you should
have another power strip (maybe an Iso-barŠ) with OVP. Always
have more than one protector in series. All wiring should be done with #12
copper. The AC cord should be a minimum # 12 gauge. The main coils are wired on
1/2"dia. PVC pipe x 8 1/4" long with 2" screws to hold off the
coil forms. Wind 59 turns of #12 Cu and leave extra wire at each end for
hookup. Use the 130vac 23mm size MOVS. Mount (2) MOVS* per leg [H to N, N
to G, H to G] and (3) MOVS on the output of the EMI filter.
The EMI filter needs to have a [bare]
#12 cu. wire soldered from its metallic case to ground. Fusing at 15A
would be better than 20A if you do not need the extra power. Making coils [5 to
7 turns, 1/4" diameter] with left over wire between hookups never hurts.
Lightning gets dizzy in the coils and quits!
Total costs =$52.50 +\ - your junk
box parts
*MOVS wear out with time and even faster
with only minor spikes. So if you
are using an OVP that is 5 years old and not
blown up; change the MOVS.
TranszorbsŠ do not wear out and
clamp voltages accurately with no over shoot.
If youÕve got the bucks, you can substitute a
General Semiconductors TranszorbŠ [#587b151, 15A, which
will blow a 15A fuse (and not blow up)
PARTS
LIST
1. 1 Pull-Box,
10"x10"x4", Hubbell SC101004, [Lowe's]
2. 1 2-socket, surface-mount
steel electrical box [Lowe's]
3. 1 Steel outlet cover
[Lowe's]
4. 1 Dual 20A AC outlet, gray
color – commercial grade [Lowe's]
5. 1 AC cord +plug #12 gauge
(Buy an extension cord and cut the outlet off).
6. 1 15A/20A ceramic 3AG fuse
+ fuse holder [Hosfelt , 31-774, 342014A]
7. 1 EMI filter,
20A [Hosfelt 927-188]
8. 2 Capacitor, .01uF @ 1.6Kv
[Digikey 495-1372-ND]
9. 1 17 in. PVC ,
1/2" [Lowe's]
10. 2 Ground lugs for
#6Cu. [Lowe's]
11. 1 AC wire clamp [Lowe's]
12. 1 1/2" steel nipple and 2 nuts to
secure outlet box [Lowe's]
13. 1 Yellow wire nut
[Lowe's]
14. 4 RF Chokes, ~ 0.12 mH
; 7 turns #12 insulated solid copper house wire, wound on ¼Ó
drill. (L1, L5 black wire, L2, L6 white wire).
14. 2 RF Chokes: ~ 10.24 mH2;
59 turns #12 insulated solid copper house wire, wound on 13/16Ó o.d. white PVC.
(L3 back wire, L4 white wire). 22 feet of wire required for each coil.
15. 22 ft. white #12 Cu solid wire [Lowe's]
16. 9 MOVS :130vac/150vac,
quarter size,23mm [Hosfelt V150LA20B]
17.
Optional General Semiconductor Industries TranszorbŠ
# 587b151 (15A), or 587b201(20A) [Arrow]
Figure 1. An AC Overvoltage Protector
Suppliers
Hosfelt; Electronics,
Inc. www.hosfelt.com
Arrow Electronics,
Inc. www.arrow.com
Digikey, Inc.
www.digikey.com
1
Consultant, Intertie, Inc.
2
Inductance values nominal, calculated as
air core inductor, using formula,
page 6.22, ARRL Handbook 2001. American Radio Relay League, Newington,
CT 06111. Permeability of PVC pipe was not considered.
‹ææææ Copyright November 10, 2004,
Intertie, Incorporated. All rights reserved
Revised: 01/01/05 04:24 PM by N5VRP, Dennis Rogers,
Webmaster
Copyright 2003 by Intertie, Inc. All Rights Reserved
No
use of these symbols or phrases is allowed without the express written
permission of Intertie, Inc.
Figure 1. An AC Overvoltage Protector
Suppliers
Hosfelt; Electronics,
Inc. www.hosfelt.com
Arrow Electronics,
Inc. www.arrow.com
Digikey, Inc.
www.digikey.com
1
Consultant, Intertie, Inc.
2
Inductance values nominal, calculated as
air core inductor, using formula,
page 6.22, ARRL Handbook 2001. American Radio Relay League, Newington,
CT 06111. Permeability of PVC pipe was not considered.
‹ææææ Copyright November 10, 2004, Intertie, Incorporated. All rights reservedRevised: 01/01/05 04:24 PM by N5VRP, Dennis Rogers, Webmaster Copyright 2003 by Intertie, Inc. All Rights Reserved No use of these symbols or phrases is allowed without the express written permission of Intertie, Inc.