Bobrick B-770 Owner's manual

DuraDry B-770, B-778
Dryer Troubleshooting and Information Guide
Effective 6/1/19
All Bobrick dryers require cleaning every 6 months to ensure that
they function effectively. Please note that failing to clean the dryer
may result in malfunction and can void the warranty.
www.bobrick.com
BOBRICK DOMESTIC
Email: [email protected]
Corporate Ofce - Los Angeles - Bobrick Washroom Equipment
6901 Tujunga Avenue, North Hollywood, California 91605-6213
Customer Service: 818.982.9600, Fax: [phone]
New York - Bobrick Washroom Equipment, Inc.
200 Commerce Drive, Clifton Park, New York 12065-1350
Customer Service: 518.877.7444, Fax: [phone]
Canada - Bobrick Washroom Equipment Company
45 Rolark Drive, Scarborough, Ontario M1R 3B1
Customer Service: Eastern Canada: 877.423.6555, Fax: [phone]
Western Canada: 877.423.6444, Fax: [phone]
BOBRICK INTERNATIONAL
Email: [email protected]
Corporate Ofce - Bobrick Washroom Equipment, Inc.
6901 Tujunga Avenue,, North Hollywood, California 91605-6213 USA
Customer Service: +1 818.764.1000, Fax: [phone];
United Kingdom Bobrick Washroom Equipment Limited
Phone: [phone], Fax: [phone]; Email: [email protected]
Germany Phone: [phone]; Email: [email protected]
Australia Bobrick Washroom Equipment Pty. Ltd.
Phone: [phone], Fax: [phone]; Email: [email protected]

DuraDry B-770, B-778 Dryers
Contents Page
Instructions For Using The Dryer Guide ..............................................3
Dryer Service Information Sheet ....................................................4
Date Code Information ...........................................................5
Routine Maintenance Instructions ...................................................6
Product Identication.............................................................7
Cover removal ..................................................................8
Diagnostic Sheet ................................................................9
Screwdriver Test ...............................................................10
Field Replacement Parts .........................................................11
Cover Replacement.............................................................12
Installation of Touch Controller ....................................................13
Installation of Base Plate Mounted Triac .............................................14
Installation of Automatic Controller .................................................15
Instructions for Installation of Sensor Board ..........................................16
Instructions for the Replacement of Motor Brushes ....................................17
Installation of Surface-Mounted Hand Dryers .........................................18
Recommended Mounting Heights. .................................................19
Schematic Diagrams ............................................................21
Warranty .....................................................................22

Instructions For Using The Dryer Guide
• Signs for your safety: General mandatory sign (to be
accompanied where necessary by
another sign)
Danger: Electricity
• Please ll out the Dryer Service Information Sheet completely. If a section is not necessary/available
insert N/A in the space.
• If the faulty dryer has been installed for 2 months or less, then replace complete dryer and return
faulty unit to the nearest Bobrick Customer Service Department.
• When you receive a call concerning a dryer problem inform, the customer/end user to clean the
dryer and check the motor brushes before going on with diagnosing the problem. Fax them the
cleaning instructions from the guide. If the dryer still does not function after cleaning,
then continue lling out the Dryer Service Information Sheet.
• Inform the customer/end user that the malfunctioning/replaced parts must be returned to the Bobrick
Customer Service Department or a charge will be made for replacement parts.

Dryer Service Information Sheet
Distributor/Rep/End-User Name: Bobrick’s best
Address: 12345 Your Street, Suite 100
City: Toon Town State: Your State Zip code: 98765
Job Name: Fantasy Lane Job Location: My Town
Contact Name: Jessica Rabbit Telephone: [phone] Fax: [phone]
Email: [email protected] Account #: 99999 Sales order #: 246810
Invoice #:35791 Invoice Date: 03/03/20
Dryer Model Information:
Automatic Dryer: __P__TouchButton Dryer: (check one)
Dryer: __P_ Dryer: _____ (check one)
Dryer model #/voltage: 700 115V
Quantity defective: 1 Quantity on job: 2 Date of installation: 06/03/20
Date code (as seen on bottom edge of cover on dryer UL label. For example: 04A): ________________________
Dryer Information:
When did dryer problems rst occur from date of installation?
(Circle one) Upon 2+ Out of
Installation Months Warranty
If dryer problem occurred within two months of installation, REPLACE dryer and return faulty dryer.
Does the dryer in any way function now? No (Yes or No)
Has the dryer been cleaned in the past 6 months? No (Yes or No). If No, send a cleaning sheet and await outcome.
Full description of fault: Unit would not start upon installation.
Reference to Diagnostic Sheets:
Problem and possible solution: Faulty controller
Problem number(s) (as seen in left margin on diagnostic sheet): # 1 F
Repair kit/parts required (if dryer needs to be returned write RETURN): Return
Part number(s) for replacements: Complete Unit Replaced on SO #: ________________
ANY DEFECTIVE PARTS MUST ACCOMPANY THIS COMPLETED SHEET TO BOBRICK’S SERVICE DEPARTMENT.
Information sheet completed by:Your Name Completion Date:6/6/20
Branch/Rep Firm: _________________________________________________________
Form No. CSD-1196 ST Rev. 4/19 Bobrick Washroom Equipment, Inc. Printed in U.S.A.
0–2
Months

Date Code Information
The date code on all Bobrick Dryers is found on the upper left corner of the rating label and on the
serial number label.
The date code will contain two digits and one letter.
The digits designate the week and the letter designates the year.
Example: 30Z week thirty, year 2000.
All digits and letters are in ascending order.
Weeks are numbered from 1 to 52 for each year.
Rating Label
Serial Number Label
Date code and
serial number
V = 2019
U = 2018
T = 2017
S = 2016
R = 2015
P = 2014
N = 2013
M = 2012
L = 2011
K = 2010
J = 2009
H = 2008
G = 2007
F = 2006
E = 2005
D = 2004
C = 2003
B = 2002
A = 2001
Z = 2000
Y = 1999
X = 1998
W = 1997
V = 1996
U = 1995
T = 1994
S = 1993
R = 1992
P = 1991
N = 1990
M = 1989

Routine Maintenance Instructions
• All Bobrick Dryers require cleaning every 6 months to ensure that they function effectively. Please
note that failing to clean the dryer may result in malfunction and can void the warranty.
• If the dryer is installed in an area prone to dust and dirt this cleaning procedure should be carried
out more frequently.
• Check the length of motor brushes, where applicable, when performing the cleaning procedure.
Cleaning Instructions:
a) The Exterior of Cover
Should be cleaned with a damp cloth, DO NOT use aggressive cleaners or solvents as they may
permanently damage the surface.
Bobrick dryers are drip proof (IP21 or better, see rating label). DO NOT spray with liquids to an
extent that they could enter the unit.
b) The Interior
Having turned off all power to the dryer, remove the cover.
Using a small brush or vacuum, carefully clean out the build up of dust and lint.
Check the length of the motor brushes. If less than ½'' replace. Check that motor brushes are i
installed correctly and that brushes are worn evenly.
Replace the cover.
Turn the power back on.
Warning
Risk of electric
shock
Disconnect power
supply before
removing cover

DuraDry Dryer
B-770 White cover
B-778 Chrome cover

Instructions for Removal of Dryer Cover
Warning
Risk of electric
shock
Disconnect power
supply before
removing cover
To Remove Cover
1. Start installation of dryer by removing cover. To loosen two cover bolts, insert Allen Wrench
(provided with dryer) into holes located on bottom of cover. Make sure wrench ts into head of cover
bolts and turn clockwise until bolts stop turning. When cover bolts are screwed out all the way, cover
can be removed.
2. To remove cover, place a hand on each side of cover and push up toward top of dryer releasing
cover from studs at top of mounting base. Lift cover off mounting base by pulling forward at the
bottom and upward at the same time.

Diagnostic Sheet for DuraDry B-770, B-778 Dryers
Problem Possible Cause Possible Solution
AUTOMATIC
1. Dryer does not run a) No electricity supply Check main supply / wiring
b) Installation fault Check service manual for possible
wiring mistakes
c) Worn motor brushes Check length of brushes; replace
if less than ½''
d) Element open circuit Return dryer to Bobrick for repair
e) Control nonstart Replace control
f) Triac open circuit Replace triac
2. Sparks from dryer Worn motor brushes Replace motor brushes
3. Dryer runs at low speed a) Worn motor brushes Replace motor brushes
b) Triac halfwave Remove white wire from triac; no
difference, replace triac
c) Control halfwave Remove white wire from triac;
dryer stops, replace control
4. Dryer runs continuously a) Triac short circuit Remove white wire from triac; no
difference, replace triac
b) Control faulty Remove white wire from triac;
dryer stops, replace control
5. Dryer cycles on and off Control Replace control
6. Dryer sometimes runs Dirty control lens Clean control lens
Control Replace control
7. Dryer is oversensitive Control Replace control
8. Dryer blows cold air or motor runs fast Heating element Return dryer to Bobrick for repairs
9. Grinding noise from dryer a) Worn motor brushes Replace motor brushes
b) Fan cage is bent or damaged Return dryer to Bobrick for repairs
10. Dryer does not run and Worn motor brushes Replace motor brushes; if still not
heating element glows functioning after replacing the
motor brushes, return dryer to
Bobrick for repairs.
TOUCHBUTTON
1. Dryer does not run a) No electricity supply Check main supply / wiring
b) Installation fault Check service manual for possible
wiring mistakes
c) Tabs are not connecting Turn off power, remove cover and
bend tabs closer to sensor board
d) Worn motor brushes Check length of brushes; replace
if less than ½''
e) Element open circuit Return dryer to Bobrick for repair
f) Timer assembly nonstart Perform Screwdriver Test (see test
instructions)
2. Sparks from dryer Worn motor brushes Replace motor brushes
3. Dryer does not run and Worn motor brushes Replace motor brushes; if still not
heating element glows functioning after replacing the
motor brushes, return dryer to
Bobrick for repairs.
4. Dryer runs at low speed a) Worn motor brushes Replace motor brushes
b) Timer assembly Replace timer assembly
5. Dryer runs continuously b) Timer assembly Replace timer assembly
6. Dryer blows cold air Heating element Return dryer to Bobrick for repair
7. Grinding noise from dryer a) Worn motor brushes Replace motor brushes
b) Fan cage is bent or damaged Return dryer to Bobrick for repair
8. Dryer is oversensitive and a) Button loose Pack button O ring with tape
switches on or off randomly b) Timer assembly or crystal board Perform Screwdriver Test (see test
instructions)
9. Dryer cycles on and off Timer assembly or crystal board Perform Screwdriver Test (see test
instructions)

Screwdriver Test for Touch Button Dryers
Warning
Risk of electric
shock
Disconnect power
supply before
removing cover
NOTE: This test instruction sheet is not for dissemination to, and should not be disseminated to, the
public including end users.
This test is designed to test the Touch Timer Assembly and the Sensor Board.
Instructions for Test:
1. Turn off the power to dryer.
2. Remove dryer cover.
3. Turn on the power. Do not touch any part of the dryer.
4. Using an insulated screwdriver, short across the two tabs (see below).
a) If dryer runs sensor board may be faulty replace sensor board.
b) If dryer does not runtimer may be faulty replace touch controller.
5. Turn off power to dryer.
6. Put dryer cover back on and turn power on.