
PENBERTHY MODEL MGS-314L SERIES LEVEL CONTROL SWITCH
INSTALLATION, OPERATION AND MAINTENANCE INSTRUCTIONS
Before installation, these instructions must be carefully read and understood.
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PRODUCT WARRANTY
Emerson warrants its products as designed 
and manufactured to be free of defects in 
material and workmanship for a period of one 
year after the date of installation or eighteen 
months after date of manufacture, whichever 
is earliest. Emerson will, at its option, replace 
or repair any products which fail during the 
warranty period due to defective material or 
workmanship.
Prior to submitting any claim for warranty 
service, the owner must submit proof of 
purchase to Emerson and obtain written 
authorization to return the product. Thereafter, 
the product shall be returned to Emerson, with 
freight prepaid.
This warranty shall not apply if the product has 
been disassembled, tampered with, repaired 
or altered outside of the Emerson factory, or 
if it has been subjected to misuse, neglect or 
accident.
TABLE OF CONTENTS
 Product Warranty.......................................... 1
1. Introduction ................................................... 1
2. Specifications/Approvals .............................. 2
 2.1 2.1 Enclosure.......................................... 2
 2.2 Switch...................................................... 2
 2.3 Approvals ................................................ 2
3. Theory of Operation....................................... 2
4. Installation..................................................... 3
 4.1 Unpacking............................................... 3
 4.2 Mounting the switch............................... 3
 4.3 Wiring connection................................... 3
5. Set-up............................................................. 4
 5.1 Initial test ................................................ 4
6. Troubleshooting ............................................ 4
 6.1 Introduction ............................................ 4
 6.2 Switch test .............................................. 4
7. Disposal at End of Useful Life ...................... 4
8. Telephone Assistance................................... 4
Emerson's responsibility hereunder is limited 
to repairing or replacing the product at its 
expense.
Emerson shall not be liable for loss, damage, 
or expenses directly or indirectly related to the 
installation or use of its products, or from any 
other cause or for consequential damages. It 
is expressly understood that Emerson is not 
responsible for damage or injury caused to 
other products, building, property or persons, 
by reason of the installation or use of its 
products.
This is Emerson's sole warranty and in lieu of 
all other warranties, expressed or implied which 
are hereby excluded, including in particular all 
warranties of merchantability or fitness for a 
particular purpose.
This document and the warranty contained 
herein may not be modified and no other 
warranty, expressed or implied, shall be made 
by or on behalf of Emerson unless modified or 
made in writing and signed by the company's 
president or a vice president.
1 INTRODUCTION
The instructions in this manual pertain to the 
Penberthy Model MGS-314L Series magnetic 
level gauge switch.
The Model MGS-314L Series magnetic level 
gauge switch is designed to detect the passage 
of the float in a Multiview™ magnetic liquid 
level gauge, at a specific location. The switch 
consists of a bi-stable latching reed switch 
encased in a watertight enclosure.
Tables and Figures
Table 1 Wire conditions at different 
switch orientations.......................... 4
Figure 1 MGS-314L switch positions ............ 2
Figure 2 Control drawing CSA approved 
explosion-proof for 
MGS-314L (7E741-008) ................... 5
Figure 3 Control drawing CSA approved 
intrinsically safe for 
MGS-314L (7E742-008) ................... 6
Figure 4 Control drawing ATEX/ 
IECEx certified explosion-proof 
for MGS-314L (7E741-010) ............. 7
Figure 5 Control drawing ATEX/ 
IECEx certified intrinsically safe 
for MGS-314L (7E741-010) ............. 8