Copyright Goodheart-Willcox Co., Inc. 221
Name __________________________________________Date _________________Class ______________________________
________3. Referring to the R3 relay below, which of the following best describes the
switching mechanism in the relay?
R1
R1
R2
R2
R3
R3
L1
N
SW
Goodheart-Willcox Publisher
A. Single-pole single-throw
B. Single-pole double-throw
C. Double-pole single-throw
D. Double-pole double-throw
________4. Referring to the wiring diagram below, which of the following components
initiates system operation?
L1 L2
X-FRMR
1
CP
COIL
VDM
VD
GV
STAT
LIM
24 V
3
4 6
Goodheart-Willcox Publisher
A. Contacts 1-3
B. Thermostat
C. Circulator pump
D. VD contacts